Package D47crunch
Standardization and analytical error propagation of Δ47 clumped-isotope measurements
Process and standardize carbonate and/or CO2 clumped-isotope analyses, from low-level data out of a dual-inlet mass spectrometer to final, “absolute” Δ47 values with fully propagated analytical error estimates.
Usage
1. Create D47data object
Start by creating a D47data object which will store and process your data.
import D47crunch
foo = D47crunch.D47data(verbose = True)
The verbose keyword specifies whether to print out extra information when calling D47data methods.
This property may be arbitrarily changed using the verbose attribute of the resulting object:
foo.verbose = False
Even before importing any analyses, our D47data object has properties which may be inspected and/or edited:
1.1 Nominal δ13CVPDB, δ18OVPDB, and Δ47 values of carbonate standards
foo.Nominal_d13C_VPDB and foo.Nominal_d18O_VPDB are dictionaries storing the δ13CVPDB and δ18OVPDB values of carbonate standards. You may freely edit these values and/or which standards to consider:
print(foo.Nominal_d13C_VPDB)
# output: {'ETH-1': 2.02, 'ETH-2': -10.17, 'ETH-3': 1.71}
print(foo.Nominal_d18O_VPDB)
# {'ETH-1': -2.19, 'ETH-2': -18.69, 'ETH-3': -1.78}
foo.Nominal_d13C_VPDB['ETH-4'] = -10.20
foo.Nominal_d18O_VPDB['ETH-4'] = -18.81
print(foo.Nominal_d13C_VPDB)
# output: {'ETH-1': 2.02, 'ETH-2': -10.17, 'ETH-3': 1.71, 'ETH-4': -10.2}
print(foo.Nominal_d18O_VPDB)
# {'ETH-1': -2.19, 'ETH-2': -18.69, 'ETH-3': -1.78, 'ETH-4': -18.81}
foo.Nominal_D47 is another dictionary, storing the absolute Δ47 values of the standards used to anchor your measurements to an absolute Δ47 reference frame.
As above, you may feely edit these values:
print(foo.Nominal_D47)
# output: {'ETH-1': 0.258, 'ETH-2': 0.256, 'ETH-3': 0.691}
foo.Nominal_D47['ETH-4'] = 0.507
print(foo.Nominal_D47)
# output: {'ETH-1': 0.258, 'ETH-2': 0.256, 'ETH-3': 0.691, 'ETH-4': 0.507}
1.2 Oxygen-17 correction parameters
The oxygen-17 correction parameters used by D47data.crunch() (see below) are specified by foo.R13_VPDB, foo.R17_VSMOW, foo.R18_VSMOW and foo.lambda_17. Default values correspond to the IUPAC values as recommended by Daëron et al. (2016) and
Schauer et al. (2016).
print(foo.R13_VPDB) # -> 0.01118 (Chang & Li, 1990)
print(foo.R17_VSMOW) # -> 0.00038475 (Assonov & Brenninkmeijer, 2003, rescaled to R13_VPDB)
print(foo.R18_VSMOW) # -> 0.0020052 (Baertschi, 1976)
print(foo.lambda_17) # -> 0.528 (Barkan & Luz, 2005)
As above, the values for these parameters may be arbitrarily redefined:
# to change the lambda value to 0.5164, leaving the other parameters unchanged:
foo.lambda_17 = 0.5164
1.3 Default method for carbon-13 and oxygen-18 standardization
By default, bulk isotopic compositions are standardized using a “two-point” affine transformation (correcting for small offsets and stretching effects) based on the carbonate standards defined in foo.Nominal_d13C_VPDB and foo.Nominal_d18O_VPDB (see above).
Optionally, you may opt instead for a “single-point” standardization approach not correcting for strecthing effects, for instance if the cabonate standards in foo.Nominal_d13C_VPDB and foo.Nominal_d18O_VPDB cover only a small fraction of the full isotopic range of your measurements.
Finally, you may also opt to perform no a posteriori standardization of bulk isotopic compositions, which implies that the quality of your final δ13C and δ18O values will depend strongly on the accuracy of your working gas composition and the linearity of your instrument.
Switching betwwen these three options can be achieved by setting foo.d13C_STANDARDIZATION_METHOD and foo.d18O_STANDARDIZATION_METHOD to '2pt', '1pt', and 'none', respectively. Note that you may later override this default behavior on a per-session basis.
1.4 Oxygen-18 acid fractionation factor
D47data processing methods always return δ18O values of CO2 analytes relative to VSMOW rather than carbonate δ18OVPDB values (which depend on sample mineralogies and acid reaction temperature). However, when using single-point or two-point δ18O standardization or when computing the bulk isotope composition of working gases based on carbonate standards (using D47data.wg()), it is necessary to specify the oxygen-18 fractionation factor associated with the phosphoric acid reaction, by setting the value of foo.ALPHA_18O_ACID_REACTION.
2. Import data
It's time to add some analyses to out D47data object.
Start with some raw data stored as CSV in a file named rawdata.csv (spaces after commas are optional). Each line corresponds to a single analysis.
The only required fields are a sample identifier (Sample), and the working-gas delta values d45, d46, d47. If no session information is provided, all analyses will be treated as belonging to a single analytical session. Alternatively, to group analyses into sessions, provide session identifiers in a Session field. If not specified by the user, a unique identifier (UID) will be assigned automatically to each analysis. Independently known oxygen-17 anomalies may be provided as D17O (in ‰ relative to VSMOW, with λ equal to D47data.lambda_17), and are assumed to be zero otherwise. Working-gas deltas d48 and d49 may also be provided, and are otherwise treated as nan.
Example rawdata.csv file:
UID, Session, Sample, d45, d46, d47, d48, d49
A01, Session1, ETH-1, 5.79502, 11.62767, 16.89351, 24.56708, 0.79486
A02, Session1, IAEA-C1, 6.21907, 11.49107, 17.27749, 24.58270, 1.56318
A03, Session1, ETH-2, -6.05868, -4.81718, -11.63506, -10.32578, 0.61352
A04, Session1, IAEA-C2, -3.86184, 4.94184, 0.60612, 10.52732, 0.57118
A05, Session1, ETH-3, 5.54365, 12.05228, 17.40555, 25.96919, 0.74608
A06, Session1, ETH-2, -6.06706, -4.87710, -11.69927, -10.64421, 1.61234
A07, Session1, ETH-1, 5.78821, 11.55910, 16.80191, 24.56423, 1.47963
A08, Session1, IAEA-C2, -3.87692, 4.86889, 0.52185, 10.40390, 1.07032
A09, Session1, ETH-3, 5.53984, 12.01344, 17.36863, 25.77145, 0.53264
A10, Session1, IAEA-C1, 6.21905, 11.44785, 17.23428, 24.30975, 1.05702
A11, Session2, ETH-1, 5.79958, 11.63130, 16.91766, 25.12232, 1.25904
A12, Session2, IAEA-C1, 6.22514, 11.51264, 17.33588, 24.92770, 2.54331
A13, Session2, ETH-2, -6.03042, -4.74644, -11.52551, -10.55907, 0.04024
A14, Session2, IAEA-C2, -3.83702, 4.99278, 0.67529, 10.73885, 0.70929
A15, Session2, ETH-3, 5.53700, 12.04892, 17.42023, 26.21793, 2.16400
A16, Session2, ETH-2, -6.06820, -4.84004, -11.68630, -10.72563, 0.04653
A17, Session2, ETH-1, 5.78263, 11.57182, 16.83519, 25.09964, 1.26283
A18, Session2, IAEA-C2, -3.85355, 4.91943, 0.58463, 10.56221, 0.71245
A19, Session2, ETH-3, 5.52227, 12.01174, 17.36841, 26.19829, 1.03740
A20, Session2, IAEA-C1, 6.21937, 11.44701, 17.26426, 24.84678, 0.76866
Reading data from rawdata.csv can be done with foo.read():
foo.read('rawdata.csv')
print('foo contains:')
print(f'{len(foo)} analyses')
print(f'{len({r["Sample"] for r in foo})} samples')
print(f'{len({r["Session"] for r in foo})} sessions')
# output:
# foo contains:
# 20 analyses
# 5 samples
# 2 sessions
At this stage, foo behaves like a list object. Yoy may slice it in the usual way (foo[:10] returns a list of the first 10 analyses) and use built-in methods in the expected way (e.g., len(foo) is equal to 20).
We can inspect the first record now stored in foo, corresponding to a single analysis:
r = foo[0]
for k in r:
print(f'r["{k}"] = {repr(r[k])}')
# output:
# r["UID"] = 'A01'
# r["Session"] = 'Session1'
# r["Sample"] = 'ETH-1'
# r["d45"] = 5.79502
# r["d46"] = 11.62767
# r["d47"] = 16.89351
# r["d48"] = 24.56708
# r["d49"] = 0.79486
2.1 Sessions
After importing records from rawdata.csv, our D47data object now has a new dictionary attribute, foo.sessions:
for session in foo.sessions:
print(f"{session:>28}:")
for k in foo.sessions[session]:
if k == 'data':
print(f"{k:>28}: [...] (too large to print)")
else:
print(f"{k:>28}: {foo.sessions[session][k]}")
print()
# output:
# Session1:
# data: [...] (too large to print)
# scrambling_drift: False
# slope_drift: False
# wg_drift: False
# d13C_standardization_method: 2pt
# d18O_standardization_method: 2pt
#
# Session2:
# data: [...] (too large to print)
# scrambling_drift: False
# slope_drift: False
# wg_drift: False
# d13C_standardization_method: 2pt
# d18O_standardization_method: 2pt
Each session in foo.sessions has the following attributes at this stage:
data: list of all the analyses in this sessionscrambling_drift,slope_drift,wg_drift: whether parametersa,b,cof the Δ47 standardization model are allowed to drift (change linearly with with time).d13C_standardization_method,d18O_standardization_method: which method to use for this session.
You may arbitrarily edit the values of d13C_standardization_method, d18O_standardization_method for any session, which will affect the results of foo.crunch().
Similarly, you may arbitrarily edit the values of scrambling_drift, slope_drift, wg_drift for any session, which will affect the results of foo.standardize().
2.2 Samples, anchors and unknowns
3. Working gas composition
There are two ways to define the isotpic composition of the working gas.
3.1 Option 1: explicit definition
Directly writing to fields d13Cwg_VPDB and d18Owg_VSMOW:
for r in foo:
if r['Session'] == 'Session1':
r['d13Cwg_VPDB'] = -3.75
r['d18Owg_VSMOW'] = 25.14
elif r['Session'] == 'Session2':
r['d13Cwg_VPDB'] = -3.74
r['d18Owg_VSMOW'] = 25.17
3.2 Option 2: based on the known composition of a sample:
# The 2 code lines below are the default settings. It is thus not
# necessary to include them unless you wish to use different values.
foo.SAMPLE_CONSTRAINING_WG_COMPOSITION = ('ETH-3', 1.71, -1.78)
foo.ALPHA_18O_ACID_REACTION = 1.00813 # (Kim et al., 2007), calcite at 90 °C
# Compute the WG composition for each session:
foo.wg()
4. Crunch the data
Now compute δ13C, δ18Ο, and raw Δ47, Δ48, Δ49 values. Note that δ18Ο is the CO2 composition. The user is responsible for any acid fractionation correction.
foo.crunch()
r = foo[0]
for k in r:
print(f'r["{k}"] = {r[k]}')
# output:
# r["UID"] = A01
# r["Session"] = Session1
# r["Sample"] = ETH-1
# r["d45"] = 5.79502
# r["d46"] = 11.62767
# r["d47"] = 16.89351
# r["d48"] = 24.56708
# r["d49"] = 0.79486
# r["d13Cwg_VPDB"] = -3.7555729459832765
# r["d18Owg_VSMOW"] = 25.1145492463934
# r["D17O"] = 0.0
# r["d13C_VPDB"] = 1.9948594073404546
# r["d18O_VSMOW"] = 37.03357105550355
# r["D47raw"] = -0.5746856128030498
# r["D48raw"] = 1.1496833191546596
# r["D49raw"] = -27.690248970251407
6. Standardization
6.1 Default approach (pooled)
The default standardization approach computes the best-fit standardization parameters (a,b,c) for each session, along with the best-fit Δ47 values of unknown samples, using a pooled regression model taking into account the relative mapping of all samples (anchors and unknowns) in (δ47, Δ47) space.
foo.standardize()
foo.table_of_sessions(verbose = True, save_to_file = False)
foo.table_of_samples(verbose = True, save_to_file = False)
The following text is output:
[table_of_sessions]
––––––––––––––––––––––––––––––– –––––––––––
N samples (anchors + unknowns) 5 (3 + 2)
N analyses (anchors + unknowns) 20 (12 + 8)
Repeatability of δ13C_VPDB 13.8 ppm
Repeatability of δ18O_VSMOW 41.9 ppm
Repeatability of Δ47 (anchors) 13.1 ppm
Repeatability of Δ47 (unknowns) 3.4 ppm
Repeatability of Δ47 (all) 9.6 ppm
Model degrees of freedom 12
Student's 95% t-factor 2.18
Standardization method pooled
––––––––––––––––––––––––––––––– –––––––––––
[table_of_sessions]
–––––––– –– –– ––––––––––– –––––––––––– –––––– –––––– –––––– ––––––––––––– ––––––––––––– ––––––––––––––
Session Na Nu d13Cwg_VPDB d18Owg_VSMOW r_d13C r_d18O r_D47 a ± SE 1e3 x b ± SE c ± SE
–––––––– –– –– ––––––––––– –––––––––––– –––––– –––––– –––––– ––––––––––––– ––––––––––––– ––––––––––––––
Session1 6 4 -3.756 25.115 0.0035 0.0415 0.0066 0.838 ± 0.016 3.340 ± 0.247 -0.859 ± 0.007
Session2 6 4 -3.743 25.118 0.0174 0.0490 0.0119 0.815 ± 0.015 4.601 ± 0.246 -0.847 ± 0.007
–––––––– –– –– ––––––––––– –––––––––––– –––––– –––––– –––––– ––––––––––––– ––––––––––––– ––––––––––––––
[table_of_samples]
––––––– – ––––––––– –––––––––– –––––– –––––– –––––––– –––––– ––––––––
Sample N d13C_VPDB d18O_VSMOW D47 SE 95% CL SD p_Levene
––––––– – ––––––––– –––––––––– –––––– –––––– –––––––– –––––– ––––––––
ETH-1 4 2.00 37.00 0.2580 0.0096
ETH-2 4 -10.03 20.18 0.2560 0.0154
ETH-3 4 1.71 37.45 0.6910 0.0039
IAEA-C1 4 2.46 36.88 0.3624 0.0061 ± 0.0133 0.0031 0.901
IAEA-C2 4 -8.04 30.19 0.7246 0.0082 ± 0.0178 0.0037 0.825
––––––– – ––––––––– –––––––––– –––––– –––––– –––––––– –––––– ––––––––
6.2 D47data.sessions
Under the hood, the normalization step does many things. It stores session information in foo.sessions:
print([k for k in foo.sessions])
# output: ['Session1', 'Session2']
for k in foo.sessions['Session1']:
if k == 'data':
print(f"{k:>16}: [...] (too large to print)")
else:
print(f"{k:>16}: {foo.sessions['Session1'][k]}")
# output:
# data: [...] (too large to print)
# scrambling_drift: False
# slope_drift: False
# wg_drift: False
# d13Cwg_VPDB: -3.7555729339153743
# d18Owg_VSMOW: 25.11497520475171
# Na: 6
# Nu: 4
# r_d13C_VPDB: 0.0035270930676685897
# r_d18O_VSMOW: 0.04146501520018946
# r_D47: 0.006638319178058144
# Np: 3
# a: 0.8381700110925523
# SE_a: 0.015603757788793743
# b: 0.003340175397346955
# SE_b: 0.0002474062198065805
# c: -0.8586981978192628
# SE_c: 0.006737855663518676
# a2: 0.0
# SE_a2: 0.0
# b2: 0.0
# SE_b2: 0.0
# c2: 0.0
# SE_c2: 0.0
# CM: [...] (6x6 numpy.Array())
each element of foo.sessions has the following attributes:
data: list of all the analyses in this sessionscrambling_drift,slope_drift,wg_drift: whether parametersa,b,care allowed to drift (change linearly with with time)d13Cwg_VPDB,d18Owg_VSMOW: working gas compositionNa: number of anchor analyses in this sessionNu: number of unknown analyses in this sessionr_d13C_VPDB,r_d18O_VSMOW,r_D47: repeatabilities ford13C_VPDB,d18O_VSMOW,D47in this sessiona,SE_a: best-fit value and model SE of scrambling factorb,SE_b: best-fit value and model SE of compositional slopec,SE_c: best-fit value and model SE of working gas offseta2,b2,c2: drift rates (per unit ofTimeTag) ofa,b,c. IfTimeTagis one of the fields in the raw data, this will be used, otherwiseTimeTagstarts at 0 for each session and increases by 1 for each analysis, in the listed order (thus beware of datasets ordered by sample name).CM: the covariance matrix of (a,b,c,a2,b2,c2).
6.3 D47data.samples, D47data.anchors, and D47data.unknowns
Additional information about the samples is stored in foo.samples (the same information can also be accessed via foo.anchors and foo.unknowns):
print([k for k in foo.samples])
# output:
# ['ETH-1', 'ETH-2', 'ETH-3', 'IAEA-C1', 'IAEA-C2']
for k in foo.samples['IAEA-C1']:
if k == 'data':
print(f"{k:>12}: [...] (too large to print)")
else:
print(f"{k:>12}: {foo.samples['IAEA-C1'][k]}")
# output:
# data: [...] (too large to print)
# N: 4
# SD_D47: 0.0031207941052170305
# d13C_VPDB: 2.460639104889639
# d18O_VSMOW: 36.87725533010137
# p_Levene: 0.901152441112675
# D47: 0.3624187694150056
# SE_D47: 0.00610711296513016
Each element of foo.samples has the following attributes:
N: total number of analyses in the whole data setSD_D47: the sample SD of Δ47 for this sampled13C_VPDB,d18O_VSMOW: average δ13C, δ18Ο values for the analyte CO2.D47,SE_D47: best-fit value and model SE for the Δ47 of this samplep_Levene: p-value for a Levene test of whether the observed Δ47 variance for this sample is significantly larger than that for ETH-3 (to change the reference sample to compare with, e.g. to ETH-1:foo.LEVENE_REF_SAMPLE = 'ETH-1'before callingfoo.normalize()).
6.4 D47data.()repeatability
The overall analytical repeatabilities are now saved to foo.repeatability:
for k in foo.repeatability:
print(f"{k:>12}: {foo.repeatability[k]}")
# output:
# r_d13C_VPDB: 0.013821704833171146
# r_d18O_VSMOW: 0.04191487414887982
# r_D47a: 0.010690471302409636
# r_D47u: 0.0034370447628642863
# r_D47: 0.008561367687546161
r_d13C_VPDB: Analytical repeatability of δ13C for all samplesr_d18O_VSMOW: Analytical repeatability of δ18O for all samples (CO2 values)r_D47a: Analytical repeatability of Δ47 for anchor samples onlyr_D47u: Analytical repeatability of Δ47 for unknown samples onlyr_D47: Analytical repeatability of Δ47 for all samples.
6.5 D47data.()result
By default foo.normalize() uses the lmfit.Minimizer.leastsq() method, which returns an instance of lmfit.MinimizerResult. This MinimizerResultinstance is stored in foo.result. A detailed report may be printed using foo.report()
print(type(foo.normalization))
# output:
# <class 'lmfit.minimizer.MinimizerResult'>
6.6 Legacy standardization approach (indep_sessions)
Following a more traditional approach, foo.standardize(method = 'indep_sessions') computes the best-fit standardization parameters (a,b,c) for each session using independent regression models (one per session) only taking into account the anchor samples (samples defined in foo.Nominal_D47), then computes the Δ47 value for each analysis and
the weighted average Δ47 value for each unknown sample.
7. Viewing and saving the results
under construction
Expand source code
#! /usr/bin/env python3
'''
Standardization and analytical error propagation of Δ47 clumped-isotope measurements
Process and standardize carbonate and/or CO<sub>2</sub> clumped-isotope analyses,
from low-level data out of a dual-inlet mass spectrometer to final, “absolute”
Δ<sub>47</sub> values with fully propagated analytical error estimates.
.. include:: ../docs/documentation.md
'''
__author__ = 'Mathieu Daëron'
__contact__ = 'daeron@lsce.ipsl.fr'
__copyright__ = 'Copyright (c) 2020 Mathieu Daëron'
__license__ = 'Modified BSD License - https://opensource.org/licenses/BSD-3-Clause'
__date__ = '2020-05-16'
__version__ = '0.5.dev3'
import os
import numpy as np
from statistics import stdev
from scipy.stats import t as tstudent
from scipy.stats import levene
from scipy.interpolate import interp1d
from numpy import linalg
from lmfit import Minimizer, Parameters, report_fit
from matplotlib import pyplot as ppl
from datetime import datetime as dt
from functools import wraps
from matplotlib import rcParams
rcParams['font.family'] = 'sans-serif'
rcParams['font.sans-serif'] = 'Helvetica'
rcParams['font.size'] = 10
rcParams['mathtext.fontset'] = 'custom'
rcParams['mathtext.rm'] = 'sans'
rcParams['mathtext.bf'] = 'sans:bold'
rcParams['mathtext.it'] = 'sans:italic'
rcParams['mathtext.cal'] = 'sans:italic'
rcParams['mathtext.default'] = 'rm'
rcParams['xtick.major.size'] = 4
rcParams['xtick.major.width'] = 1
rcParams['ytick.major.size'] = 4
rcParams['ytick.major.width'] = 1
rcParams['axes.grid'] = False
rcParams['axes.linewidth'] = 1
rcParams['grid.linewidth'] = .75
rcParams['grid.linestyle'] = '-'
rcParams['grid.alpha'] = .15
rcParams['savefig.dpi'] = 150
Petersen_etal_CO2eqD47 = np.array([[-12, 1.147113572], [-11, 1.139961218], [-10, 1.132872856], [-9, 1.125847677], [-8, 1.118884889], [-7, 1.111983708], [-6, 1.105143366], [-5, 1.098363105], [-4, 1.091642182], [-3, 1.084979862], [-2, 1.078375423], [-1, 1.071828156], [0, 1.065337360], [1, 1.058902349], [2, 1.052522443], [3, 1.046196976], [4, 1.039925291], [5, 1.033706741], [6, 1.027540690], [7, 1.021426510], [8, 1.015363585], [9, 1.009351306], [10, 1.003389075], [11, 0.997476303], [12, 0.991612409], [13, 0.985796821], [14, 0.980028975], [15, 0.974308318], [16, 0.968634304], [17, 0.963006392], [18, 0.957424055], [19, 0.951886769], [20, 0.946394020], [21, 0.940945302], [22, 0.935540114], [23, 0.930177964], [24, 0.924858369], [25, 0.919580851], [26, 0.914344938], [27, 0.909150167], [28, 0.903996080], [29, 0.898882228], [30, 0.893808167], [31, 0.888773459], [32, 0.883777672], [33, 0.878820382], [34, 0.873901170], [35, 0.869019623], [36, 0.864175334], [37, 0.859367901], [38, 0.854596929], [39, 0.849862028], [40, 0.845162813], [41, 0.840498905], [42, 0.835869931], [43, 0.831275522], [44, 0.826715314], [45, 0.822188950], [46, 0.817696075], [47, 0.813236341], [48, 0.808809404], [49, 0.804414926], [50, 0.800052572], [51, 0.795722012], [52, 0.791422922], [53, 0.787154979], [54, 0.782917869], [55, 0.778711277], [56, 0.774534898], [57, 0.770388426], [58, 0.766271562], [59, 0.762184010], [60, 0.758125479], [61, 0.754095680], [62, 0.750094329], [63, 0.746121147], [64, 0.742175856], [65, 0.738258184], [66, 0.734367860], [67, 0.730504620], [68, 0.726668201], [69, 0.722858343], [70, 0.719074792], [71, 0.715317295], [72, 0.711585602], [73, 0.707879469], [74, 0.704198652], [75, 0.700542912], [76, 0.696912012], [77, 0.693305719], [78, 0.689723802], [79, 0.686166034], [80, 0.682632189], [81, 0.679122047], [82, 0.675635387], [83, 0.672171994], [84, 0.668731654], [85, 0.665314156], [86, 0.661919291], [87, 0.658546854], [88, 0.655196641], [89, 0.651868451], [90, 0.648562087], [91, 0.645277352], [92, 0.642014054], [93, 0.638771999], [94, 0.635551001], [95, 0.632350872], [96, 0.629171428], [97, 0.626012487], [98, 0.622873870], [99, 0.619755397], [100, 0.616656895], [102, 0.610519107], [104, 0.604459143], [106, 0.598475670], [108, 0.592567388], [110, 0.586733026], [112, 0.580971342], [114, 0.575281125], [116, 0.569661187], [118, 0.564110371], [120, 0.558627545], [122, 0.553211600], [124, 0.547861454], [126, 0.542576048], [128, 0.537354347], [130, 0.532195337], [132, 0.527098028], [134, 0.522061450], [136, 0.517084654], [138, 0.512166711], [140, 0.507306712], [142, 0.502503768], [144, 0.497757006], [146, 0.493065573], [148, 0.488428634], [150, 0.483845370], [152, 0.479314980], [154, 0.474836677], [156, 0.470409692], [158, 0.466033271], [160, 0.461706674], [162, 0.457429176], [164, 0.453200067], [166, 0.449018650], [168, 0.444884242], [170, 0.440796174], [172, 0.436753787], [174, 0.432756438], [176, 0.428803494], [178, 0.424894334], [180, 0.421028350], [182, 0.417204944], [184, 0.413423530], [186, 0.409683531], [188, 0.405984383], [190, 0.402325531], [192, 0.398706429], [194, 0.395126543], [196, 0.391585347], [198, 0.388082324], [200, 0.384616967], [202, 0.381188778], [204, 0.377797268], [206, 0.374441954], [208, 0.371122364], [210, 0.367838033], [212, 0.364588505], [214, 0.361373329], [216, 0.358192065], [218, 0.355044277], [220, 0.351929540], [222, 0.348847432], [224, 0.345797540], [226, 0.342779460], [228, 0.339792789], [230, 0.336837136], [232, 0.333912113], [234, 0.331017339], [236, 0.328152439], [238, 0.325317046], [240, 0.322510795], [242, 0.319733329], [244, 0.316984297], [246, 0.314263352], [248, 0.311570153], [250, 0.308904364], [252, 0.306265654], [254, 0.303653699], [256, 0.301068176], [258, 0.298508771], [260, 0.295975171], [262, 0.293467070], [264, 0.290984167], [266, 0.288526163], [268, 0.286092765], [270, 0.283683684], [272, 0.281298636], [274, 0.278937339], [276, 0.276599517], [278, 0.274284898], [280, 0.271993211], [282, 0.269724193], [284, 0.267477582], [286, 0.265253121], [288, 0.263050554], [290, 0.260869633], [292, 0.258710110], [294, 0.256571741], [296, 0.254454286], [298, 0.252357508], [300, 0.250281174], [302, 0.248225053], [304, 0.246188917], [306, 0.244172542], [308, 0.242175707], [310, 0.240198194], [312, 0.238239786], [314, 0.236300272], [316, 0.234379441], [318, 0.232477087], [320, 0.230593005], [322, 0.228726993], [324, 0.226878853], [326, 0.225048388], [328, 0.223235405], [330, 0.221439711], [332, 0.219661118], [334, 0.217899439], [336, 0.216154491], [338, 0.214426091], [340, 0.212714060], [342, 0.211018220], [344, 0.209338398], [346, 0.207674420], [348, 0.206026115], [350, 0.204393315], [355, 0.200378063], [360, 0.196456139], [365, 0.192625077], [370, 0.188882487], [375, 0.185226048], [380, 0.181653511], [385, 0.178162694], [390, 0.174751478], [395, 0.171417807], [400, 0.168159686], [405, 0.164975177], [410, 0.161862398], [415, 0.158819521], [420, 0.155844772], [425, 0.152936426], [430, 0.150092806], [435, 0.147312286], [440, 0.144593281], [445, 0.141934254], [450, 0.139333710], [455, 0.136790195], [460, 0.134302294], [465, 0.131868634], [470, 0.129487876], [475, 0.127158722], [480, 0.124879906], [485, 0.122650197], [490, 0.120468398], [495, 0.118333345], [500, 0.116243903], [505, 0.114198970], [510, 0.112197471], [515, 0.110238362], [520, 0.108320625], [525, 0.106443271], [530, 0.104605335], [535, 0.102805877], [540, 0.101043985], [545, 0.099318768], [550, 0.097629359], [555, 0.095974915], [560, 0.094354612], [565, 0.092767650], [570, 0.091213248], [575, 0.089690648], [580, 0.088199108], [585, 0.086737906], [590, 0.085306341], [595, 0.083903726], [600, 0.082529395], [605, 0.081182697], [610, 0.079862998], [615, 0.078569680], [620, 0.077302141], [625, 0.076059794], [630, 0.074842066], [635, 0.073648400], [640, 0.072478251], [645, 0.071331090], [650, 0.070206399], [655, 0.069103674], [660, 0.068022424], [665, 0.066962168], [670, 0.065922439], [675, 0.064902780], [680, 0.063902748], [685, 0.062921909], [690, 0.061959837], [695, 0.061016122], [700, 0.060090360], [705, 0.059182157], [710, 0.058291131], [715, 0.057416907], [720, 0.056559120], [725, 0.055717414], [730, 0.054891440], [735, 0.054080860], [740, 0.053285343], [745, 0.052504565], [750, 0.051738210], [755, 0.050985971], [760, 0.050247546], [765, 0.049522643], [770, 0.048810974], [775, 0.048112260], [780, 0.047426227], [785, 0.046752609], [790, 0.046091145], [795, 0.045441581], [800, 0.044803668], [805, 0.044177164], [810, 0.043561831], [815, 0.042957438], [820, 0.042363759], [825, 0.041780573], [830, 0.041207664], [835, 0.040644822], [840, 0.040091839], [845, 0.039548516], [850, 0.039014654], [855, 0.038490063], [860, 0.037974554], [865, 0.037467944], [870, 0.036970054], [875, 0.036480707], [880, 0.035999734], [885, 0.035526965], [890, 0.035062238], [895, 0.034605393], [900, 0.034156272], [905, 0.033714724], [910, 0.033280598], [915, 0.032853749], [920, 0.032434032], [925, 0.032021309], [930, 0.031615443], [935, 0.031216300], [940, 0.030823749], [945, 0.030437663], [950, 0.030057915], [955, 0.029684385], [960, 0.029316951], [965, 0.028955498], [970, 0.028599910], [975, 0.028250075], [980, 0.027905884], [985, 0.027567229], [990, 0.027234006], [995, 0.026906112], [1000, 0.026583445], [1005, 0.026265908], [1010, 0.025953405], [1015, 0.025645841], [1020, 0.025343124], [1025, 0.025045163], [1030, 0.024751871], [1035, 0.024463160], [1040, 0.024178947], [1045, 0.023899147], [1050, 0.023623680], [1055, 0.023352467], [1060, 0.023085429], [1065, 0.022822491], [1070, 0.022563577], [1075, 0.022308615], [1080, 0.022057533], [1085, 0.021810260], [1090, 0.021566729], [1095, 0.021326872], [1100, 0.021090622]])
_fCO2eqD47_Petersen = interp1d(Petersen_etal_CO2eqD47[:,0], Petersen_etal_CO2eqD47[:,1])
def fCO2eqD47_Petersen(T):
'''
CO<sub>2</sub> equilibrium Δ<sub>47</sub> value as a function of `T` (in degrees C)
according to [Petersen et al. (2019)].
[Petersen et al. (2019)]: https://doi.org/10.1029/2018GC008127
'''
return float(_fCO2eqD47_Petersen(T))
Wang_etal_CO2eqD47 = np.array([[-83., 1.8954], [-73., 1.7530], [-63., 1.6261], [-53., 1.5126], [-43., 1.4104], [-33., 1.3182], [-23., 1.2345], [-13., 1.1584], [-3., 1.0888], [7., 1.0251], [17., 0.9665], [27., 0.9125], [37., 0.8626], [47., 0.8164], [57., 0.7734], [67., 0.7334], [87., 0.6612], [97., 0.6286], [107., 0.5980], [117., 0.5693], [127., 0.5423], [137., 0.5169], [147., 0.4930], [157., 0.4704], [167., 0.4491], [177., 0.4289], [187., 0.4098], [197., 0.3918], [207., 0.3747], [217., 0.3585], [227., 0.3431], [237., 0.3285], [247., 0.3147], [257., 0.3015], [267., 0.2890], [277., 0.2771], [287., 0.2657], [297., 0.2550], [307., 0.2447], [317., 0.2349], [327., 0.2256], [337., 0.2167], [347., 0.2083], [357., 0.2002], [367., 0.1925], [377., 0.1851], [387., 0.1781], [397., 0.1714], [407., 0.1650], [417., 0.1589], [427., 0.1530], [437., 0.1474], [447., 0.1421], [457., 0.1370], [467., 0.1321], [477., 0.1274], [487., 0.1229], [497., 0.1186], [507., 0.1145], [517., 0.1105], [527., 0.1068], [537., 0.1031], [547., 0.0997], [557., 0.0963], [567., 0.0931], [577., 0.0901], [587., 0.0871], [597., 0.0843], [607., 0.0816], [617., 0.0790], [627., 0.0765], [637., 0.0741], [647., 0.0718], [657., 0.0695], [667., 0.0674], [677., 0.0654], [687., 0.0634], [697., 0.0615], [707., 0.0597], [717., 0.0579], [727., 0.0562], [737., 0.0546], [747., 0.0530], [757., 0.0515], [767., 0.0500], [777., 0.0486], [787., 0.0472], [797., 0.0459], [807., 0.0447], [817., 0.0435], [827., 0.0423], [837., 0.0411], [847., 0.0400], [857., 0.0390], [867., 0.0380], [877., 0.0370], [887., 0.0360], [897., 0.0351], [907., 0.0342], [917., 0.0333], [927., 0.0325], [937., 0.0317], [947., 0.0309], [957., 0.0302], [967., 0.0294], [977., 0.0287], [987., 0.0281], [997., 0.0274], [1007., 0.0268], [1017., 0.0261], [1027., 0.0255], [1037., 0.0249], [1047., 0.0244], [1057., 0.0238], [1067., 0.0233], [1077., 0.0228], [1087., 0.0223], [1097., 0.0218]])
_fCO2eqD47_Wang = interp1d(Wang_etal_CO2eqD47[:,0] - 0.15, Wang_etal_CO2eqD47[:,1])
def fCO2eqD47_Wang(T):
'''
CO<sub>2</sub> equilibrium Δ<sub>47</sub> value as a function of `T` (in degrees C)
according to [Wang et al. (2004)] (supplementary data of [Dennis et al., 2011]).
[Wang et al. (2004)]: https://doi.org/10.1016/j.gca.2004.05.039
[Dennis et al., 2011]: https://doi.org/10.1016/j.gca.2011.09.025
'''
return float(_fCO2eqD47_Wang(T))
def correlated_sum(X,C,f = ''):
'''
Compute covariance-aware linear combinations
Return the mean and SE of the sum of the elements of `X`, with optional
weights corresponding to the elements of `f`, accounting for `C`,
the covariance matrix of `X`.
'''
if f == '':
f = [1 for x in X]
return np.dot(f,X), (np.dot(f,np.dot(C,f)))**.5
def make_csv(x, hsep = ',', vsep = '\n'):
'''
Formats a list of lists of strings as a CSV
__Parameters__
+ `x`: the list of lists of strings to format
+ `hsep`: the field separator (a comma, by default)
+ `vsep`: the line-ending convention to use (`'\\n'` by default)
__Example__
```python
x = [['a', 'b', 'c'], ['d', 'e', 'f']]
print(make_csv(x))
```
output:
```python
a,b,c
d,e,f
```
'''
return vsep.join([hsep.join(l) for l in x])
def pf(txt):
'''
Modify string `txt` to follow `lmfit.Parameter()` naming rules.
'''
return txt.replace('-','_').replace('.','_').replace(' ','_')
def smart_type(x):
'''
Tries to convert string `x` to a float if it includes a decimal point, or
to an integer if it does not. If both attempts fail, return the original
string unchanged.
'''
try:
y = float(x)
except ValueError:
return x
if '.' not in x:
return int(y)
return y
def pretty_table(x, header = 1, hsep = ' ', vsep = '–', align = '<'):
'''
Reads a list of lists of strings and outputs an ascii table
__Parameters__
+ `x`: a list of lists of strings
+ `header`: the number of lines to treat as header lines
+ `hsep`: the horizontal separator between columns
+ `vsep`: the character to use as vertical separator
+ `align`: string of left (`<`) or right (`>`) alignment characters.
__Example__
```python
x = [['A','B', 'C'], ['1', '1.9999', 'foo'], ['10', 'x', 'bar']]
print(pretty_table(x))
```
output:
```python
-- ------ ---
A B C
-- ------ ---
1 1.9999 foo
10 x bar
-- ------ ---
```
'''
txt = []
widths = [np.max([len(e) for e in c]) for c in zip(*x)]
if len(widths) > len(align):
align += '>' * (len(widths)-len(align))
sepline = hsep.join([vsep*w for w in widths])
txt += [sepline]
for k,l in enumerate(x):
if k and k == header:
txt += [sepline]
txt += [hsep.join([f'{e:{a}{w}}' for e, w, a in zip(l, widths, align)])]
txt += [sepline]
txt += ['']
return '\n'.join(txt)
def transpose_table(x):
'''
Transpose a list if lists
__Parameters__
+ `x`: a list of lists
__Example__
```python
x = [[1, 2], [3, 4]]
print(transpose_table(x))
```
outputs:
```python
[[1, 3], [2, 4]]
```
'''
return [[e for e in c] for c in zip(*x)]
def w_avg(X, sX) :
'''
Compute variance-weighted average
Returns the value and SE of the weighted average of the elements of `X`,
with relative weights equal to their inverse variances (`1/sX**2`).
__Parameters__
+ `X`: array-like of elements to average
+ `sX`: array-like of the corresponding SE values
__Tip__
If `X` and `sX` are initially arranged as a list of `(x, sx)` doublets,
they may be rearranged using `zip()`:
```python
foo = [(0, 0.1), (1, 0.05), (2, 0.05)]
print(w_avg(*zip(*foo)))
# output:
# (1.3333333333333333, 0.03333333333333334)
```
'''
X = [ x for x in X ]
sX = [ sx for sx in sX ]
W = [ sx**-2 for sx in sX ]
W = [ w/sum(W) for w in W ]
Xavg = sum([ w*x for w,x in zip(W,X) ])
sXavg = sum([ w**2*sx**2 for w,sx in zip(W,sX) ])**.5
return Xavg, sXavg
class D47data(list):
'''
Store and process data for a large set of Δ<sub>47</sub> analyses,
usually comprising more than one analytical session.
'''
### 17O CORRECTION PARAMETERS
R13_VPDB = 0.01118 # (Chang & Li, 1990)
'''
Absolute (<sup>13</sup>C/<sup>12</sup>C) ratio of VPDB.
By default equal to 0.01118 ([Chang & Li, 1990])
[Chang & Li, 1990]: http://www.cnki.com.cn/Article/CJFDTotal-JXTW199004006.htm
'''
R18_VSMOW = 0.0020052 # (Baertschi, 1976)
'''
Absolute (<sup>18</sup>O/<sup>16</sup>C) ratio of VSMOW.
By default equal to 0.0020052 ([Baertschi, 1976])
[Baertschi, 1976]: https://doi.org/10.1016/0012-821X(76)90115-1
'''
lambda_17 = 0.528 # (Barkan & Luz, 2005)
'''
Mass-dependent exponent for triple oxygen isotopes.
By default equal to 0.528 ([Barkan & Luz, 2005])
[Barkan & Luz, 2005]: https://doi.org/10.1002/rcm.2250
'''
R17_VSMOW = 0.00038475 # (Assonov & Brenninkmeijer, 2003, rescaled to R13_VPDB)
'''
Absolute (<sup>17</sup>O/<sup>16</sup>C) ratio of VSMOW.
By default equal to 0.00038475
([Assonov & Brenninkmeijer, 2003], rescaled to `R13_VPDB`)
[Assonov & Brenninkmeijer, 2003]: https://dx.doi.org/10.1002/rcm.1011
'''
R18_VPDB = R18_VSMOW * 1.03092
'''
Absolute (<sup>18</sup>O/<sup>16</sup>C) ratio of VPDB.
By definition equal to `R18_VSMOW * 1.03092`.
'''
R17_VPDB = R17_VSMOW * 1.03092 ** lambda_17
'''
Absolute (<sup>17</sup>O/<sup>16</sup>C) ratio of VPDB.
By definition equal to `R17_VSMOW * 1.03092 ** lambda_17`.
'''
LEVENE_REF_SAMPLE = 'ETH-3'
'''
After the Δ<sub>47</sub> standardization step, each sample is tested to
assess whether the Δ<sub>47</sub> variance within all analyses for that
sample differs significantly from that observed for a given reference
sample (using [Levene's test], which yields a p-value corresponding to
the null hypothesis that the underlying variances are equal).
`LEVENE_REF_SAMPLE` (by default equal to `'ETH-3'`) specifies which
sample should be used as a reference for this test.
[Levene's test]: https://en.wikipedia.org/wiki/Levene%27s_test
'''
SAMPLE_CONSTRAINING_WG_COMPOSITION = ('ETH-3', 1.71, -1.78) # (Bernasconi et al., 2018)
'''
Specifies the name, δ<sup>13</sup>C<sub>VPDB</sub> and δ<sup>18</sup>O<sub>VPDB</sub>
of the carbonate standard used by `D47data.wg()` to compute the isotopic composition
of the working gas in each session.
By default equal to `('ETH-3', 1.71, -1.78)` after [Bernasconi et al. (2018)].
[Bernasconi et al. (2018)]: https://doi.org/10.1029/2017GC007385
'''
ALPHA_18O_ACID_REACTION = round(np.exp(3.59 / (90 + 273.15) - 1.79e-3), 6) # (Kim et al., 2007, calcite)
'''
Specifies the <sup>18</sup>O/<sup>16</sup>O fractionation factor generally applicable
to acid reactions in the dataset. Currently used by `D47data.wg()`,
`D47data.standardize_d13C`, and `D47data.standardize_d18O`.
By default equal to 1.008129 (calcite reacted at 90 °C, [Kim et al., 2007]).
[Kim et al., 2007]: https://dx.doi.org/10.1016/j.chemgeo.2007.08.005
'''
Nominal_D47 = {
'ETH-1': 0.258,
'ETH-2': 0.256,
'ETH-3': 0.691,
} # (Bernasconi et al., 2018)
'''
Nominal Δ<sub>47</sub> values assigned to the anchor samples, used by
`D47data.standardize()` to standardize unknown samples to an absolute Δ<sub>47</sub>
reference frame.
By default equal to `{'ETH-1': 0.258, 'ETH-2': 0.256, 'ETH-3': 0.691}` after
[Bernasconi et al. (2018)].
[Bernasconi et al. (2018)]: https://doi.org/10.1029/2017GC007385
'''
Nominal_d13C_VPDB = {
'ETH-1': 2.02,
'ETH-2': -10.17,
'ETH-3': 1.71,
} # (Bernasconi et al., 2018)
'''
Nominal δ<sup>13</sup>C<sub>VPDB</sub> values assigned to carbonate standards, used by
`D47data.standardize_d13C()`.
By default equal to `{'ETH-1': 2.02, 'ETH-2': -10.17, 'ETH-3': 1.71}` after
[Bernasconi et al. (2018)].
[Bernasconi et al. (2018)]: https://doi.org/10.1029/2017GC007385
'''
Nominal_d18O_VPDB = {
'ETH-1': -2.19,
'ETH-2': -18.69,
'ETH-3': -1.78,
} # (Bernasconi et al., 2018)
'''
Nominal δ<sup>18</sup>O<sub>VPDB</sub> values assigned to carbonate standards, used by
`D47data.standardize_d18O()`.
By default equal to `{'ETH-1': -2.19, 'ETH-2': -18.69, 'ETH-3': -1.78}` after
[Bernasconi et al. (2018)].
[Bernasconi et al. (2018)]: https://doi.org/10.1029/2017GC007385
'''
d13C_STANDARDIZATION_METHOD = '2pt'
'''
Method by which to standardize δ<sup>13</sup>C values:
+ `none`: do not apply any δ<sup>13</sup>C standardization.
+ `'1pt'`: within each session, offset all initial δ<sup>13</sup>C values so as to
minimize the difference between final δ<sup>13</sup>C<sub>VPDB</sub> values and
`Nominal_d13C_VPDB` (averaged over all analyses for which `Nominal_d13C_VPDB` is defined).
+ `'2pt'`: within each session, apply a affine trasformation to all δ<sup>13</sup>C
values so as to minimize the difference between final δ<sup>13</sup>C<sub>VPDB</sub>
values and `Nominal_d13C_VPDB` (averaged over all analyses for which `Nominal_d13C_VPDB`
is defined).
'''
d18O_STANDARDIZATION_METHOD = '2pt'
'''
Method by which to standardize δ<sup>18</sup>O values:
+ `none`: do not apply any δ<sup>18</sup>O standardization.
+ `'1pt'`: within each session, offset all initial δ<sup>18</sup>O values so as to
minimize the difference between final δ<sup>18</sup>O<sub>VPDB</sub> values and
`Nominal_d18O_VPDB` (averaged over all analyses for which `Nominal_d18O_VPDB` is defined).
+ `'2pt'`: within each session, apply a affine trasformation to all δ<sup>18</sup>O
values so as to minimize the difference between final δ<sup>18</sup>O<sub>VPDB</sub>
values and `Nominal_d18O_VPDB` (averaged over all analyses for which `Nominal_d18O_VPDB`
is defined).
'''
def __init__(self, l = [], logfile = '', session = 'mySession', verbose = False):
'''
__Parameters__
+ `l`: a list of dictionaries, with each dictionary including at least the keys
`Sample`, `d45`, `d46`, and `d47`.
+ `logfile`: if specified, write detailed logs to this file path when calling `D47data`
methods.
+ `session`: define session name for analyses without a `Session` key
+ `verbose`: if `True`, print out detailed logs when calling `D47data`
methods.
Returns a `D47data` object derived from `list`.
'''
self.verbose = verbose
self.prefix = 'D47data'
self.logfile = logfile
list.__init__(self, l)
self.Nf = None
self.repeatability = {}
self.refresh(session = session)
def make_verbal(oldfun):
'''
Decorator to temporarily change `self.prefix`
and allow locally overriding `self.verbose`
'''
@wraps(oldfun)
def newfun(*args, verbose = '', **kwargs):
myself = args[0]
oldprefix = myself.prefix
myself.prefix = oldfun.__name__
if verbose != '':
oldverbose = myself.verbose
myself.verbose = verbose
out = oldfun(*args, **kwargs)
myself.prefix = oldprefix
if verbose != '':
myself.verbose = oldverbose
return out
return newfun
def msg(self, txt):
'''
Log a message to `self.logfile`, and print it out if `verbose = True`
'''
self.log(txt)
if self.verbose:
print(f'{f"[{self.prefix}]":<16} {txt}')
def vmsg(self, txt):
'''
Log a message to `self.logfile` and print it out
'''
self.log(txt)
print(txt)
def log(self, *txts):
'''
Log a message to `self.logfile`
'''
if self.logfile:
with open(self.logfile, 'a') as fid:
for txt in txts:
fid.write(f'\n{dt.now().strftime("%Y-%m-%d %H:%M:%S")} {f"[{self.prefix}]":<16} {txt}')
def refresh(self, session = 'mySession'):
'''
Update `self.sessions`, `self.samples`, `self.anchors`, and `self.unknowns`.
'''
self.fill_in_missing_info(session = session)
self.refresh_sessions()
self.refresh_samples()
def refresh_sessions(self):
'''
Update `self.sessions` and set `scrambling_drift`, `slope_drift`, and `wg_drift`
to `False` for all sessions.
'''
self.sessions = {
s: {'data': [r for r in self if r['Session'] == s]}
for s in sorted({r['Session'] for r in self})
}
for s in self.sessions:
self.sessions[s]['scrambling_drift'] = False
self.sessions[s]['slope_drift'] = False
self.sessions[s]['wg_drift'] = False
self.sessions[s]['d13C_standardization_method'] = self.d13C_STANDARDIZATION_METHOD
self.sessions[s]['d18O_standardization_method'] = self.d18O_STANDARDIZATION_METHOD
def refresh_samples(self):
'''
Define `self.samples`, `self.anchors`, and `self.unknowns`.
'''
self.samples = {
s: {'data': [r for r in self if r['Sample'] == s]}
for s in sorted({r['Sample'] for r in self})
}
self.anchors = {s: self.samples[s] for s in self.samples if s in self.Nominal_D47}
self.unknowns = {s: self.samples[s] for s in self.samples if s not in self.Nominal_D47}
def read(self, filename, sep = '', session = ''):
'''
Read file in csv format to load data into a `D47data` object.
In the csv file, spaces befor and after field separators (`','` by default)
are optional. Each line corresponds to a single analysis.
The required fields are:
+ `UID`: a unique identifier
+ `Session`: an identifier for the analytical session
+ `Sample`: a sample identifier
+ `d45`, `d46`, `d47`: the working-gas delta values
Independently known oxygen-17 anomalies may be provided as `D17O` (in ‰ relative to
VSMOW, λ = `self.lambda_17`), and are otherwise assumed to be zero. Working-gas deltas `d48`
and `d49` may also be provided, and are also set to 0 otherwise.
__Parameters__
+ `fileneme`: the path of the file to read
+ `sep`: csv separator delimiting the fields
+ `session`: set `Session` field to this string for all analyses
'''
with open(filename) as fid:
self.input(fid.read(), sep = sep, session = session)
def input(self, txt, sep = '', session = ''):
'''
Read `txt` string in csv format to load analysis data into a `D47data` object.
In the csv string, spaces befor and after field separators (`','` by default)
are optional. Each line corresponds to a single analysis.
The required fields are:
+ `UID`: a unique identifier
+ `Session`: an identifier for the analytical session
+ `Sample`: a sample identifier
+ `d45`, `d46`, `d47`: the working-gas delta values
Independently known oxygen-17 anomalies may be provided as `D17O` (in ‰ relative to
VSMOW, λ = `self.lambda_17`), and are otherwise assumed to be zero. Working-gas deltas `d48`
and `d49` may also be provided, and are also set to 0 otherwise.
__Parameters__
+ `txt`: the csv string to read
+ `sep`: csv separator delimiting the fields. By default, use `,`, `;`, or `\t`,
whichever appers most often in `txt`.
+ `session`: set `Session` field to this string for all analyses
'''
if sep == '':
sep = sorted(',;\t', key = lambda x: - txt.count(x))[0]
txt = [[x.strip() for x in l.split(sep)] for l in txt.splitlines() if l.strip()]
data = [{k: v if k in ['UID', 'Session', 'Sample'] else smart_type(v) for k,v in zip(txt[0], l)} for l in txt[1:]]
if session != '':
for r in data:
r['Session'] = session
self += data
self.refresh()
@make_verbal
def wg(self, samples = '', a18_acid = ''):
'''
Compute bulk composition of the working gas for each session
based on the carbonate standards defined both in `self.Nominal_d13C_VPDB`
and in `self.Nominal_d18O_VPDB`.
'''
self.msg('Computing WG composition:')
if a18_acid == '':
a18_acid = self.ALPHA_18O_ACID_REACTION
if samples == '':
samples = [s for s in self.Nominal_d13C_VPDB if s in self.Nominal_d18O_VPDB]
assert a18_acid, f'Acid fractionation value should differ from zero.'
samples = [s for s in samples if s in self.Nominal_d13C_VPDB and s in self.Nominal_d18O_VPDB]
R45R46_standards = {}
for sample in samples:
d13C_vpdb = self.Nominal_d13C_VPDB[sample]
d18O_vpdb = self.Nominal_d18O_VPDB[sample]
R13_s = self.R13_VPDB * (1 + d13C_vpdb / 1000)
R17_s = self.R17_VPDB * ((1 + d18O_vpdb / 1000) * a18_acid) ** self.lambda_17
R18_s = self.R18_VPDB * (1 + d18O_vpdb / 1000) * a18_acid
C12_s = 1 / (1 + R13_s)
C13_s = R13_s / (1 + R13_s)
C16_s = 1 / (1 + R17_s + R18_s)
C17_s = R17_s / (1 + R17_s + R18_s)
C18_s = R18_s / (1 + R17_s + R18_s)
C626_s = C12_s * C16_s ** 2
C627_s = 2 * C12_s * C16_s * C17_s
C628_s = 2 * C12_s * C16_s * C18_s
C636_s = C13_s * C16_s ** 2
C637_s = 2 * C13_s * C16_s * C17_s
C727_s = C12_s * C17_s ** 2
R45_s = (C627_s + C636_s) / C626_s
R46_s = (C628_s + C637_s + C727_s) / C626_s
R45R46_standards[sample] = (R45_s, R46_s)
for s in self.sessions:
db = [r for r in self.sessions[s]['data'] if r['Sample'] in samples]
assert db, f'No sample from {samples} found in session "{s}".'
# dbsamples = sorted({r['Sample'] for r in db})
X = [r['d45'] for r in db]
Y = [R45R46_standards[r['Sample']][0] for r in db]
x1, x2 = np.min(X), np.max(X)
wgcoord = x1/(x1-x2)
if wgcoord < -.5 or wgcoord > 1.5:
# unreasonable to extrapolate to d45 = 0
R45_wg = np.mean([y/(1+x/1000) for x,y in zip(X,Y)])
else :
# d45 = 0 is reasonably well bracketed
R45_wg = np.polyfit(X, Y, 1)[1]
X = [r['d46'] for r in db]
Y = [R45R46_standards[r['Sample']][1] for r in db]
x1, x2 = np.min(X), np.max(X)
wgcoord = x1/(x1-x2)
if wgcoord < -.5 or wgcoord > 1.5:
# unreasonable to extrapolate to d46 = 0
R46_wg = np.mean([y/(1+x/1000) for x,y in zip(X,Y)])
else :
# d46 = 0 is reasonably well bracketed
R46_wg = np.polyfit(X, Y, 1)[1]
d13Cwg_VPDB, d18Owg_VSMOW = self.compute_bulk_delta(R45_wg, R46_wg)
self.msg(f'Session {s} WG: δ13C_VPDB = {d13Cwg_VPDB:.3f} δ18O_VSMOW = {d18Owg_VSMOW:.3f}')
self.sessions[s]['d13Cwg_VPDB'] = d13Cwg_VPDB
self.sessions[s]['d18Owg_VSMOW'] = d18Owg_VSMOW
for r in self.sessions[s]['data']:
r['d13Cwg_VPDB'] = d13Cwg_VPDB
r['d18Owg_VSMOW'] = d18Owg_VSMOW
@make_verbal
def wg_old(self, sample = '', d13C_vpdb = '', d18O_vpdb = '', a18_acid = ''):
'''
Compute bulk composition of the working gas for each session
based on the average composition, within each session,
of a given sample.
'''
self.msg('Computing WG composition:')
if sample == '':
sample = self.SAMPLE_CONSTRAINING_WG_COMPOSITION[0]
if d13C_vpdb == '':
d13C_vpdb = self.SAMPLE_CONSTRAINING_WG_COMPOSITION[1]
if d18O_vpdb == '':
d18O_vpdb = self.SAMPLE_CONSTRAINING_WG_COMPOSITION[2]
if a18_acid == '':
a18_acid = self.ALPHA_18O_ACID_REACTION
assert a18_acid, f'Acid fractionation value should differ from zero.'
R13_s = self.R13_VPDB * (1 + d13C_vpdb / 1000)
R17_s = self.R17_VPDB * ((1 + d18O_vpdb / 1000) * a18_acid) ** self.lambda_17
R18_s = self.R18_VPDB * (1 + d18O_vpdb / 1000) * a18_acid
C12_s = 1 / (1 + R13_s)
C13_s = R13_s / (1 + R13_s)
C16_s = 1 / (1 + R17_s + R18_s)
C17_s = R17_s / (1 + R17_s + R18_s)
C18_s = R18_s / (1 + R17_s + R18_s)
C626_s = C12_s * C16_s ** 2
C627_s = 2 * C12_s * C16_s * C17_s
C628_s = 2 * C12_s * C16_s * C18_s
C636_s = C13_s * C16_s ** 2
C637_s = 2 * C13_s * C16_s * C17_s
C727_s = C12_s * C17_s ** 2
R45_s = (C627_s + C636_s) / C626_s
R46_s = (C628_s + C637_s + C727_s) / C626_s
for s in self.sessions:
db = [r for r in self.sessions[s]['data'] if r['Sample'] == sample]
assert db, f'Sample "{sample}" not found in session "{s}".'
d45_s = np.mean([r['d45'] for r in db])
d46_s = np.mean([r['d46'] for r in db])
R45_wg = R45_s / (1 + d45_s / 1000)
R46_wg = R46_s / (1 + d46_s / 1000)
d13Cwg_VPDB, d18Owg_VSMOW = self.compute_bulk_delta(R45_wg, R46_wg)
self.msg(f'Session {s} WG: δ13C_VPDB = {d13Cwg_VPDB:.3f} δ18O_VSMOW = {d18Owg_VSMOW:.3f}')
self.sessions[s]['d13Cwg_VPDB'] = d13Cwg_VPDB
self.sessions[s]['d18Owg_VSMOW'] = d18Owg_VSMOW
for r in self.sessions[s]['data']:
r['d13Cwg_VPDB'] = d13Cwg_VPDB
r['d18Owg_VSMOW'] = d18Owg_VSMOW
def compute_bulk_delta(self, R45, R46, D17O = 0):
'''
Compute δ<sup>13</sup>C<sub>VPDB</sub> and δ<sup>18</sup>O<sub>VSMOW</sub>,
by solving the generalized form of equation (17) from [Brand et al. (2010)],
assuming that δ<sup>18</sup>O<sub>VSMOW</sub> is not too big (0 ± 50 ‰) and
solving the corresponding second-order Taylor polynomial.
(Appendix A of [Daëron et al., 2016])
[Brand et al. (2010)]: https://doi.org/10.1351/PAC-REP-09-01-05
[Daëron et al., 2016]: https://doi.org/10.1016/j.chemgeo.2016.08.014
'''
K = np.exp(D17O / 1000) * self.R17_VSMOW * self.R18_VSMOW ** -self.lambda_17
A = -3 * K ** 2 * self.R18_VSMOW ** (2 * self.lambda_17)
B = 2 * K * R45 * self.R18_VSMOW ** self.lambda_17
C = 2 * self.R18_VSMOW
D = -R46
aa = A * self.lambda_17 * (2 * self.lambda_17 - 1) + B * self.lambda_17 * (self.lambda_17 - 1) / 2
bb = 2 * A * self.lambda_17 + B * self.lambda_17 + C
cc = A + B + C + D
d18O_VSMOW = 1000 * (-bb + (bb ** 2 - 4 * aa * cc) ** .5) / (2 * aa)
R18 = (1 + d18O_VSMOW / 1000) * self.R18_VSMOW
R17 = K * R18 ** self.lambda_17
R13 = R45 - 2 * R17
d13C_VPDB = 1000 * (R13 / self.R13_VPDB - 1)
return d13C_VPDB, d18O_VSMOW
def D47fromTeq(self, fCo2eqD47 = 'petersen', priority = 'new'):
'''
Find all samples for which `Teq` is specified, compute equilibrium Δ<sub>47</sub>
value for that temperature, and add treat these samples as additional anchors.
__Parameters__
+ `fCo2eqD47`: Which CO<sub>2</sub> equilibrium law to use
(`petersen`: [Petersen et al. (2019)];
`wang`: [Wang et al. (2019)]).
+ `priority`: if `replace`: forget old anchors and only use the new ones;
if `new`: keep pre-existing anchors but update them in case of conflict
between old and new Δ<sub>47</sub> values;
if `old`: keep pre-existing anchors but preserve their original Δ<sub>47</sub>
values in case of conflict.
[Petersen et al. (2019)]: https://doi.org/10.1029/2018GC008127
[Wang et al. (2019)]: https://doi.org/10.1016/j.gca.2004.05.039
'''
f = {
'petersen': fCO2eqD47_Petersen,
'wang': fCO2eqD47_Wang,
}[fCo2eqD47]
foo = {}
for r in self:
if 'Teq' in r:
if r['Sample'] in foo:
assert foo[r['Sample']] == f(r['Teq']), f'Different values of `Teq` provided for sample `{r["Sample"]}`.'
else:
foo[r['Sample']] = f(r['Teq'])
else:
assert r['Sample'] not in foo, f'`Teq` is inconsistently specified for sample `{r["Sample"]}`.'
if priority == 'replace':
self.Nominal_D47 = {}
for s in foo:
if priority != 'old' or s not in self.Nominal_D47:
self.Nominal_D47[s] = foo[s]
@make_verbal
def crunch(self, verbose = ''):
'''
Compute bulk composition and raw clumped isotope anomalies for all analyses.
'''
for r in self:
self.compute_bulk_and_clumping_deltas(r)
self.standardize_d13C()
self.standardize_d18O()
self.msg(f"Crunched {len(self)} analyses.")
def fill_in_missing_info(self, session = 'mySession'):
'''
Fill in optional fields with default values
'''
for i,r in enumerate(self):
if 'D17O' not in r:
r['D17O'] = 0.
if 'UID' not in r:
r['UID'] = f'#{i+1}'
if 'Session' not in r:
r['Session'] = session
for k in ['d48', 'd49']:
if k not in r:
r[k] = np.nan
def standardize_d13C(self):
'''
Perform δ<sup>13</sup>C standadization within each session `s` according to
`self.sessions[s]['d13C_standardization_method']`, which is defined by default
by `D47data.refresh_sessions()`as equal to `self.d13C_STANDARDIZATION_METHOD`, but
may be redefined abitrarily at a later stage.
'''
for s in self.sessions:
if self.sessions[s]['d13C_standardization_method'] in ['1pt', '2pt']:
XY = [(r['d13C_VPDB'], self.Nominal_d13C_VPDB[r['Sample']]) for r in self.sessions[s]['data'] if r['Sample'] in self.Nominal_d13C_VPDB]
X,Y = zip(*XY)
if self.sessions[s]['d13C_standardization_method'] == '1pt':
offset = np.mean(Y) - np.mean(X)
for r in self.sessions[s]['data']:
r['d13C_VPDB'] += offset
elif self.sessions[s]['d13C_standardization_method'] == '2pt':
a,b = np.polyfit(X,Y,1)
for r in self.sessions[s]['data']:
r['d13C_VPDB'] = a * r['d13C_VPDB'] + b
def standardize_d18O(self):
'''
Perform δ<sup>18</sup>O standadization within each session `s` according to
`self.ALPHA_18O_ACID_REACTION` and `self.sessions[s]['d18O_standardization_method']`,
which is defined by default by `D47data.refresh_sessions()`as equal to
`self.d18O_STANDARDIZATION_METHOD`, but may be redefined abitrarily at a later stage.
'''
for s in self.sessions:
if self.sessions[s]['d18O_standardization_method'] in ['1pt', '2pt']:
XY = [(r['d18O_VSMOW'], self.Nominal_d18O_VPDB[r['Sample']]) for r in self.sessions[s]['data'] if r['Sample'] in self.Nominal_d18O_VPDB]
X,Y = zip(*XY)
Y = [(1000+y) * self.R18_VPDB * self.ALPHA_18O_ACID_REACTION / self.R18_VSMOW - 1000 for y in Y]
if self.sessions[s]['d18O_standardization_method'] == '1pt':
offset = np.mean(Y) - np.mean(X)
for r in self.sessions[s]['data']:
r['d18O_VSMOW'] += offset
elif self.sessions[s]['d18O_standardization_method'] == '2pt':
a,b = np.polyfit(X,Y,1)
for r in self.sessions[s]['data']:
r['d18O_VSMOW'] = a * r['d18O_VSMOW'] + b
def compute_bulk_and_clumping_deltas(self, r):
'''
Compute δ<sup>13</sup>C<sub>VPDB</sub>, δ<sup>18</sup>O<sub>VSMOW</sub>, and
raw Δ<sub>47</sub>, Δ<sub>48</sub>, Δ<sub>49</sub> values for an analysis `r`.
'''
# Compute working gas R13, R18, and isobar ratios
R13_wg = self.R13_VPDB * (1 + r['d13Cwg_VPDB'] / 1000)
R18_wg = self.R18_VSMOW * (1 + r['d18Owg_VSMOW'] / 1000)
R45_wg, R46_wg, R47_wg, R48_wg, R49_wg = self.compute_isobar_ratios(R13_wg, R18_wg)
# Compute analyte isobar ratios
R45 = (1 + r['d45'] / 1000) * R45_wg
R46 = (1 + r['d46'] / 1000) * R46_wg
R47 = (1 + r['d47'] / 1000) * R47_wg
R48 = (1 + r['d48'] / 1000) * R48_wg
R49 = (1 + r['d49'] / 1000) * R49_wg
r['d13C_VPDB'], r['d18O_VSMOW'] = self.compute_bulk_delta(R45, R46, D17O = r['D17O'])
R13 = (1 + r['d13C_VPDB'] / 1000) * self.R13_VPDB
R18 = (1 + r['d18O_VSMOW'] / 1000) * self.R18_VSMOW
# Compute stochastic isobar ratios of the analyte
R45stoch, R46stoch, R47stoch, R48stoch, R49stoch = self.compute_isobar_ratios(
R13, R18, D17O = r['D17O']
)
# Check that R45/R45stoch and R46/R46stoch are undistinguishable from 1,
# and raise a warning if the corresponding anomalies exceed 0.02 ppm.
if (R45 / R45stoch - 1) > 5e-8:
self.vmsg(f'This is unexpected: R45/R45stoch - 1 = {1e6 * (R45 / R45stoch - 1):.3f} ppm')
if (R46 / R46stoch - 1) > 5e-8:
self.vmsg(f'This is unexpected: R46/R46stoch - 1 = {1e6 * (R46 / R46stoch - 1):.3f} ppm')
# Compute raw clumped isotope anomalies
r['D47raw'] = 1000 * (R47 / R47stoch - 1)
r['D48raw'] = 1000 * (R48 / R48stoch - 1)
r['D49raw'] = 1000 * (R49 / R49stoch - 1)
def compute_isobar_ratios(self, R13, R18, D17O=0, D47=0, D48=0, D49=0):
'''
Compute isobar ratios for a sample with isotopic ratios `R13` and `R18`,
optionally accounting for non-zero values of Δ<sup>17</sup>O (`D17O`) and clumped isotope
anomalies (`D47`, `D48`, `D49`), all expressed in permil.
'''
# Compute R17
R17 = self.R17_VSMOW * np.exp(D17O / 1000) * (R18 / self.R18_VSMOW) ** self.lambda_17
# Compute isotope concentrations
C12 = (1 + R13) ** -1
C13 = C12 * R13
C16 = (1 + R17 + R18) ** -1
C17 = C16 * R17
C18 = C16 * R18
# Compute stochastic isotopologue concentrations
C626 = C16 * C12 * C16
C627 = C16 * C12 * C17 * 2
C628 = C16 * C12 * C18 * 2
C636 = C16 * C13 * C16
C637 = C16 * C13 * C17 * 2
C638 = C16 * C13 * C18 * 2
C727 = C17 * C12 * C17
C728 = C17 * C12 * C18 * 2
C737 = C17 * C13 * C17
C738 = C17 * C13 * C18 * 2
C828 = C18 * C12 * C18
C838 = C18 * C13 * C18
# Compute stochastic isobar ratios
R45 = (C636 + C627) / C626
R46 = (C628 + C637 + C727) / C626
R47 = (C638 + C728 + C737) / C626
R48 = (C738 + C828) / C626
R49 = C838 / C626
# Account for stochastic anomalies
R47 *= 1 + D47 / 1000
R48 *= 1 + D48 / 1000
R49 *= 1 + D49 / 1000
# Return isobar ratios
return R45, R46, R47, R48, R49
def split_samples(self, samples_to_split = 'all', grouping = 'by_uid'):
'''
Split unknown samples by UID (treat all analyses as different samples)
or by session (treat analyses of a given sample in different sessions as
different samples).
__Parameters__
+ `samples_to_split`: a list of samples to split, e.g., `['IAEA-C1', 'IAEA-C2']`
+ `grouping`: `by_uid` | `by_session`
'''
if samples_to_split == 'all':
samples_to_split = [s for s in self.unknowns]
gkeys = {'by_uid':'UID', 'by_session':'Session'}
self.grouping = grouping.lower()
if self.grouping in gkeys:
gkey = gkeys[self.grouping]
for r in self:
if r['Sample'] in samples_to_split:
r['Sample_original'] = r['Sample']
r['Sample'] = f"{r['Sample']}__{r[gkey]}"
elif r['Sample'] in self.unknowns:
r['Sample_original'] = r['Sample']
self.refresh_samples()
def unsplit_samples(self, tables = True):
'''
Reverse the effects of `D47data.split_samples`.
'''
unknowns_old = sorted({s for s in self.unknowns})
CM_old = self.standardization.covar[:,:]
VD_old = self.standardization.params.valuesdict().copy()
vars_old = self.standardization.var_names
unknowns_new = sorted({r['Sample_original'] for r in self if 'Sample_original' in r})
Ns = len(vars_old) - len(unknowns_old)
vars_new = vars_old[:Ns] + [f'D47_{pf(u)}' for u in unknowns_new]
VD_new = {k: VD_old[k] for k in vars_old[:Ns]}
W = np.zeros((len(vars_new), len(vars_old)))
W[:Ns,:Ns] = np.eye(Ns)
for u in unknowns_new:
splits = sorted({r['Sample'] for r in self if 'Sample_original' in r and r['Sample_original'] == u})
if self.grouping == 'by_session':
weights = [self.samples[s]['SE_D47']**-2 for s in splits]
elif self.grouping == 'by_uid':
weights = [1 for s in splits]
sw = sum(weights)
weights = [w/sw for w in weights]
W[vars_new.index(f'D47_{pf(u)}'),[vars_old.index(f'D47_{pf(s)}') for s in splits]] = weights[:]
# print('\nUnsplitting weights matrix:')
# print('\n'.join([' '.join([f'{x:.1f}' if x else ' - ' for x in l]) for l in W]))
# print('---')
CM_new = W @ CM_old @ W.T
V = W @ np.array([[VD_old[k]] for k in vars_old])
VD_new = {k:v[0] for k,v in zip(vars_new, V)}
self.standardization.covar = CM_new
self.standardization.params.valuesdict = lambda : VD_new
self.standardization.var_names = vars_new
for r in self:
if r['Sample'] in self.unknowns:
r['Sample_split'] = r['Sample']
r['Sample'] = r['Sample_original']
self.refresh_samples()
self.consolidate_samples()
self.repeatabilies()
if tables:
self.table_of_analyses()
self.table_of_samples()
def assign_timestamps(self):
'''
Assign a time field `t` of type `float` to each analysis.
If `TimeTag` is one of the data fields, `t` is equal within a given session
to `TimeTag` minus the mean value of `TimeTag` for that session.
Otherwise, `TimeTag` is by default equal to the index of each analysis
in the dataset and `t` is defined as above.
'''
for session in self.sessions:
sdata = self.sessions[session]['data']
try:
t0 = np.mean([r['TimeTag'] for r in sdata])
for r in sdata:
r['t'] = r['TimeTag'] - t0
# print('DEBUG - USING TimeTag <-----------------------------------')
except KeyError:
t0 = (len(sdata)-1)/2
for t,r in enumerate(sdata):
r['t'] = t - t0
@make_verbal
def standardize(self,
method = 'pooled',
weighted_sessions = [],
consolidate = True,
consolidate_tables = False,
consolidate_plots = False,
):
'''
Compute absolute Δ<sub>47</sub> values for all replicate analyses and for sample averages.
If `method` argument is set to `'pooled'`, the standardization processes all sessions
in a single step, assuming that all samples (anchors and unknowns alike) are
homogeneous (i.e. that their true Δ<sub>47</sub> value does not change between sessions).
If `method` argument is set to `'indep_sessions'`, the standardization processes each
session independently, based only on anchors analyses.
'''
self.standardization_method = method
self.assign_timestamps()
if method == 'pooled':
if weighted_sessions:
for session_group in weighted_sessions:
X = D47data([r for r in self if r['Session'] in session_group])
result = X.standardize(method = 'pooled', weighted_sessions = [], consolidate = False)
w = np.sqrt(result.redchi)
self.msg(f'Session group {session_group} MRSWD = {w:.4f}')
for r in X:
r['wD47raw'] *= w
else:
self.msg('All D47raw weights set to 1 ‰')
for r in self:
r['wD47raw'] = 1.
params = Parameters()
for k,session in enumerate(self.sessions):
self.msg(f"Session {session}: scrambling_drift is {self.sessions[session]['scrambling_drift']}.")
self.msg(f"Session {session}: slope_drift is {self.sessions[session]['slope_drift']}.")
self.msg(f"Session {session}: wg_drift is {self.sessions[session]['wg_drift']}.")
s = pf(session)
params.add(f'a_{s}', value = 0.9)
params.add(f'b_{s}', value = 0.)
params.add(f'c_{s}', value = -0.9)
params.add(f'a2_{s}', value = 0., vary = self.sessions[session]['scrambling_drift'])
params.add(f'b2_{s}', value = 0., vary = self.sessions[session]['slope_drift'])
params.add(f'c2_{s}', value = 0., vary = self.sessions[session]['wg_drift'])
for sample in self.unknowns:
params.add(f'D47_{pf(sample)}', value=0.6)
def residuals(p):
R = []
for r in self:
session = pf(r['Session'])
sample = pf(r['Sample'])
if r['Sample'] in self.Nominal_D47:
R += [ (
r['D47raw'] - (
p[f'a_{session}'] * self.Nominal_D47[r['Sample']]
+ p[f'b_{session}'] * r['d47']
+ p[f'c_{session}']
+ r['t'] * (
p[f'a2_{session}'] * self.Nominal_D47[r['Sample']]
+ p[f'b2_{session}'] * r['d47']
+ p[f'c2_{session}']
)
)
) / r['wD47raw'] ]
else:
R += [ (
r['D47raw'] - (
p[f'a_{session}'] * p[f'D47_{sample}']
+ p[f'b_{session}'] * r['d47']
+ p[f'c_{session}']
+ r['t'] * (
p[f'a2_{session}'] * p[f'D47_{sample}']
+ p[f'b2_{session}'] * r['d47']
+ p[f'c2_{session}']
)
)
) / r['wD47raw'] ]
return R
M = Minimizer(residuals, params)
result = M.leastsq()
self.Nf = result.nfree
self.t95 = tstudent.ppf(1 - 0.05/2, self.Nf)
# if self.verbose:
# report_fit(result)
for r in self:
s = pf(r["Session"])
a = result.params.valuesdict()[f'a_{s}']
b = result.params.valuesdict()[f'b_{s}']
c = result.params.valuesdict()[f'c_{s}']
a2 = result.params.valuesdict()[f'a2_{s}']
b2 = result.params.valuesdict()[f'b2_{s}']
c2 = result.params.valuesdict()[f'c2_{s}']
r['D47'] = (r['D47raw'] - c - b * r['d47'] - c2 * r['t'] - b2 * r['t'] * r['d47']) / (a + a2 * r['t'])
self.standardization = result
if consolidate:
self.consolidate(tables = consolidate_tables, plots = consolidate_plots)
return result
elif method == 'indep_sessions':
if weighted_sessions:
for session_group in weighted_sessions:
X = D47data([r for r in self if r['Session'] in session_group])
X.Nominal_D47 = self.Nominal_D47.copy()
X.refresh()
# This is only done to assign r['wD47raw'] for r in X:
X.standardize(method = method, weighted_sessions = [], consolidate = False)
self.msg(f'D47raw weights set to {1000*X[0]["wD47raw"]:.1f} ppm for sessions in {session_group}')
else:
self.msg('All weights set to 1 ‰')
for r in self:
r['wD47raw'] = 1
for session in self.sessions:
s = self.sessions[session]
p_names = ['a', 'b', 'c', 'a2', 'b2', 'c2']
p_active = [True, True, True, s['scrambling_drift'], s['slope_drift'], s['wg_drift']]
s['Np'] = sum(p_active)
sdata = s['data']
A = np.array([
[
self.Nominal_D47[r['Sample']] / r['wD47raw'],
r['d47'] / r['wD47raw'],
1 / r['wD47raw'],
self.Nominal_D47[r['Sample']] * r['t'] / r['wD47raw'],
r['d47'] * r['t'] / r['wD47raw'],
r['t'] / r['wD47raw']
]
for r in sdata if r['Sample'] in self.anchors
])[:,p_active] # only keep columns for the active parameters
Y = np.array([[r['D47raw'] / r['wD47raw']] for r in sdata if r['Sample'] in self.anchors])
s['Na'] = Y.size
CM = linalg.inv(A.T @ A)
bf = (CM @ A.T @ Y).T[0,:]
k = 0
for n,a in zip(p_names, p_active):
if a:
s[n] = bf[k]
# self.msg(f'{n} = {bf[k]}')
k += 1
else:
s[n] = 0.
# self.msg(f'{n} = 0.0')
for r in sdata :
a, b, c, a2, b2, c2 = s['a'], s['b'], s['c'], s['a2'], s['b2'], s['c2']
r['D47'] = (r['D47raw'] - c - b * r['d47'] - c2 * r['t'] - b2 * r['t'] * r['d47']) / (a + a2 * r['t'])
r['wD47'] = r['wD47raw'] / (a + a2 * r['t'])
s['CM'] = np.zeros((6,6))
i = 0
k_active = [j for j,a in enumerate(p_active) if a]
for j,a in enumerate(p_active):
if a:
s['CM'][j,k_active] = CM[i,:]
i += 1
if not weighted_sessions:
w = self.rmswd()['rmswd']
for r in self:
r['wD47'] *= w
r['wD47raw'] *= w
for session in self.sessions:
self.sessions[session]['CM'] *= w**2
for session in self.sessions:
s = self.sessions[session]
s['SE_a'] = s['CM'][0,0]**.5
s['SE_b'] = s['CM'][1,1]**.5
s['SE_c'] = s['CM'][2,2]**.5
s['SE_a2'] = s['CM'][3,3]**.5
s['SE_b2'] = s['CM'][4,4]**.5
s['SE_c2'] = s['CM'][5,5]**.5
if not weighted_sessions:
self.Nf = len(self) - len(self.unknowns) - np.sum([self.sessions[s]['Np'] for s in self.sessions])
else:
self.Nf = 0
for sg in weighted_sessions:
self.Nf += self.rmswd(sessions = sg)['Nf']
self.t95 = tstudent.ppf(1 - 0.05/2, self.Nf)
avgD47 = {
sample: np.mean([r['D47'] for r in self if r['Sample'] == sample])
for sample in self.samples
}
chi2 = np.sum([(r['D47'] - avgD47[r['Sample']])**2 for r in self])
rD47 = (chi2/self.Nf)**.5
self.repeatability['sigma_47'] = rD47
if consolidate:
self.consolidate(tables = consolidate_tables, plots = consolidate_plots)
def report(self):
'''
Prints a report on the standardization fit.
'''
report_fit(self.standardization)
def standardization_error(self, session, d47, D47, t = 0):
'''
Compute standardization error for a given session and
(δ<sub>47</sub>, Δ<sub>47</sub>) composition.
'''
a = self.sessions[session]['a']
b = self.sessions[session]['b']
c = self.sessions[session]['c']
a2 = self.sessions[session]['a2']
b2 = self.sessions[session]['b2']
c2 = self.sessions[session]['c2']
CM = self.sessions[session]['CM']
x, y = D47, d47
z = a * x + b * y + c + a2 * x * t + b2 * y * t + c2 * t
# x = (z - b*y - b2*y*t - c - c2*t) / (a+a2*t)
dxdy = -(b+b2*t) / (a+a2*t)
dxdz = 1. / (a+a2*t)
dxda = -x / (a+a2*t)
dxdb = -y / (a+a2*t)
dxdc = -1. / (a+a2*t)
dxda2 = -x * a2 / (a+a2*t)
dxdb2 = -y * t / (a+a2*t)
dxdc2 = -t / (a+a2*t)
V = np.array([dxda, dxdb, dxdc, dxda2, dxdb2, dxdc2])
sx = (V @ CM @ V.T) ** .5
return sx
@make_verbal
def summary(self,
dir = 'results',
filename = 'summary.csv',
save_to_file = True,
print_out = True):
'''
Print out an/or save to disk a summary of the standardization results.
__Parameters__
+ `dir`: the directory in which to save the table
+ `filename`: the name to the csv file to write to
+ `save_to_file`: whether to save the table to disk
+ `print_out`: whether to print out the table
'''
out = []
out += [['N samples (anchors + unknowns)', f"{len(self.samples)} ({len(self.anchors)} + {len(self.unknowns)})"]]
out += [['N analyses (anchors + unknowns)', f"{len(self)} ({len([r for r in self if r['Sample'] in self.anchors])} + {len([r for r in self if r['Sample'] in self.unknowns])})"]]
out += [['Repeatability of δ13C_VPDB', f"{1000 * self.repeatability['r_d13C_VPDB']:.1f} ppm"]]
out += [['Repeatability of δ18O_VSMOW', f"{1000 * self.repeatability['r_d18O_VSMOW']:.1f} ppm"]]
out += [['Repeatability of Δ47 (anchors)', f"{1000 * self.repeatability['r_D47a']:.1f} ppm"]]
out += [['Repeatability of Δ47 (unknowns)', f"{1000 * self.repeatability['r_D47u']:.1f} ppm"]]
out += [['Repeatability of Δ47 (all)', f"{1000 * self.repeatability['r_D47']:.1f} ppm"]]
out += [['Model degrees of freedom', f"{self.Nf}"]]
out += [['Student\'s 95% t-factor', f"{self.t95:.2f}"]]
out += [['Standardization method', self.standardization_method]]
if save_to_file:
if not os.path.exists(dir):
os.makedirs(dir)
with open(f'{dir}/{filename}', 'w') as fid:
fid.write(make_csv(out))
if print_out:
self.msg('\n' + pretty_table(out, header = 0))
return out
@make_verbal
def table_of_sessions(self,
dir = 'results',
filename = 'sessions.csv',
save_to_file = True,
print_out = True):
'''
Print out an/or save to disk a table of sessions.
__Parameters__
+ `dir`: the directory in which to save the table
+ `filename`: the name to the csv file to write to
+ `save_to_file`: whether to save the table to disk
+ `print_out`: whether to print out the table
'''
include_a2 = any([self.sessions[session]['scrambling_drift'] for session in self.sessions])
include_b2 = any([self.sessions[session]['slope_drift'] for session in self.sessions])
include_c2 = any([self.sessions[session]['wg_drift'] for session in self.sessions])
out = [['Session','Na','Nu','d13Cwg_VPDB','d18Owg_VSMOW','r_d13C','r_d18O','r_D47','a ± SE','1e3 x b ± SE','c ± SE']]
if include_a2:
out[-1] += ['a2 ± SE']
if include_b2:
out[-1] += ['b2 ± SE']
if include_c2:
out[-1] += ['c2 ± SE']
for session in self.sessions:
out += [[
session,
f"{self.sessions[session]['Na']}",
f"{self.sessions[session]['Nu']}",
f"{self.sessions[session]['d13Cwg_VPDB']:.3f}",
f"{self.sessions[session]['d18Owg_VSMOW']:.3f}",
f"{self.sessions[session]['r_d13C_VPDB']:.4f}",
f"{self.sessions[session]['r_d18O_VSMOW']:.4f}",
f"{self.sessions[session]['r_D47']:.4f}",
f"{self.sessions[session]['a']:.3f} ± {self.sessions[session]['SE_a']:.3f}",
f"{1e3*self.sessions[session]['b']:.3f} ± {1e3*self.sessions[session]['SE_b']:.3f}",
f"{self.sessions[session]['c']:.3f} ± {self.sessions[session]['SE_c']:.3f}",
]]
if include_a2:
if self.sessions[session]['scrambling_drift']:
out[-1] += [f"{self.sessions[session]['a2']:.1e} ± {self.sessions[session]['SE_a2']:.1e}"]
else:
out[-1] += ['']
if include_b2:
if self.sessions[session]['slope_drift']:
out[-1] += [f"{self.sessions[session]['b2']:.1e} ± {self.sessions[session]['SE_b2']:.1e}"]
else:
out[-1] += ['']
if include_c2:
if self.sessions[session]['wg_drift']:
out[-1] += [f"{self.sessions[session]['c2']:.1e} ± {self.sessions[session]['SE_c2']:.1e}"]
else:
out[-1] += ['']
if save_to_file:
if not os.path.exists(dir):
os.makedirs(dir)
with open(f'{dir}/{filename}', 'w') as fid:
fid.write(make_csv(out))
if print_out:
self.msg('\n' + pretty_table(out))
return out
@make_verbal
def table_of_analyses(self, dir = 'results', filename = 'analyses.csv', save_to_file = True, print_out = True):
'''
Print out an/or save to disk a table of analyses.
__Parameters__
+ `dir`: the directory in which to save the table
+ `filename`: the name to the csv file to write to
+ `save_to_file`: whether to save the table to disk
+ `print_out`: whether to print out the table
'''
out = [['UID','Session','Sample']]
extra_fields = [f for f in [('SampleMass','.2f'),('ColdFingerPressure','.1f'),('AcidReactionYield','.3f')] if f[0] in {k for r in self for k in r}]
for f in extra_fields:
out[-1] += [f[0]]
out[-1] += ['d13Cwg_VPDB','d18Owg_VSMOW','d45','d46','d47','d48','d49','d13C_VPDB','d18O_VSMOW','D47raw','D48raw','D49raw','D47']
for r in self:
out += [[f"{r['UID']}",f"{r['Session']}",f"{r['Sample']}"]]
for f in extra_fields:
out[-1] += [f"{r[f[0]]:{f[1]}}"]
out[-1] += [
f"{r['d13Cwg_VPDB']:.3f}",
f"{r['d18Owg_VSMOW']:.3f}",
f"{r['d45']:.6f}",
f"{r['d46']:.6f}",
f"{r['d47']:.6f}",
f"{r['d48']:.6f}",
f"{r['d49']:.6f}",
f"{r['d13C_VPDB']:.6f}",
f"{r['d18O_VSMOW']:.6f}",
f"{r['D47raw']:.6f}",
f"{r['D48raw']:.6f}",
f"{r['D49raw']:.6f}",
f"{r['D47']:.6f}"
]
if save_to_file:
if not os.path.exists(dir):
os.makedirs(dir)
with open(f'{dir}/{filename}', 'w') as fid:
fid.write(make_csv(out))
if print_out:
self.msg('\n' + pretty_table(out))
return out
@make_verbal
def table_of_samples(self, dir = 'results', filename = 'samples.csv', save_to_file = True, print_out = True):
'''
Print out an/or save to disk a table of samples.
__Parameters__
+ `dir`: the directory in which to save the table
+ `filename`: the name to the csv file to write to
+ `save_to_file`: whether to save the table to disk
+ `print_out`: whether to print out the table
'''
out = [['Sample','N','d13C_VPDB','d18O_VSMOW','D47','SE','95% CL','SD','p_Levene']]
for sample in self.anchors:
out += [[
f"{sample}",
f"{self.samples[sample]['N']}",
f"{self.samples[sample]['d13C_VPDB']:.2f}",
f"{self.samples[sample]['d18O_VSMOW']:.2f}",
f"{self.samples[sample]['D47']:.4f}",'','',
f"{self.samples[sample]['SD_D47']:.4f}" if self.samples[sample]['N'] > 1 else '', ''
]]
for sample in self.unknowns:
out += [[
f"{sample}",
f"{self.samples[sample]['N']}",
f"{self.samples[sample]['d13C_VPDB']:.2f}",
f"{self.samples[sample]['d18O_VSMOW']:.2f}",
f"{self.samples[sample]['D47']:.4f}",
f"{self.samples[sample]['SE_D47']:.4f}",
f"± {self.samples[sample]['SE_D47']*self.t95:.4f}",
f"{self.samples[sample]['SD_D47']:.4f}" if self.samples[sample]['N'] > 1 else '',
f"{self.samples[sample]['p_Levene']:.3f}" if self.samples[sample]['N'] > 2 else ''
]]
if save_to_file:
if not os.path.exists(dir):
os.makedirs(dir)
with open(f'{dir}/{filename}', 'w') as fid:
fid.write(make_csv(out))
if print_out:
self.msg('\n'+pretty_table(out))
return out
def plot_sessions(self, dir = 'plots', figsize = (8,8)):
'''
Generate session plots and save them to disk.
__Parameters__
+ `dir`: the directory in which to save the plots
+ `figsize`: the width and height (in inches) of each plot
'''
if not os.path.exists(dir):
os.makedirs(dir)
for session in self.sessions:
sp = self.plot_single_session(session, xylimits = 'constant')
ppl.savefig(f'{dir}/D47model_{session}.pdf')
ppl.close(sp.fig)
# def plot_sessions_old(self, dir = 'plots', figsize = (8,8)):
# '''
# Generate session plots and save them to disk.
#
# __Parameters__
#
# + `dir`: the directory in which to save the plots
# + `figsize`: the width and height (in inches) of each plot
# '''
# if not os.path.exists(dir):
# os.makedirs(dir)
# anchor_color = 'r'
# unknown_color = 'b'
#
# xmin = min([r['d47'] for r in self])
# xmax = max([r['d47'] for r in self])
# xmin -= (xmax - xmin)/10
# xmax += (xmax - xmin)/11
#
# ymin = min([r['D47'] for r in self])
# ymax = max([r['D47'] for r in self])
# ymin -= (ymax - ymin)/10
# ymax += (ymax - ymin)/11
#
# repl_kw = dict(ls = 'None', marker = 'x', mfc = 'None', ms = 4, mew = .67, alpha = 1)
# avg_kw = dict(ls = '-', marker = 'None', lw = .67, alpha = .67)
# for session in self.sessions:
# fig = ppl.figure( figsize = figsize)
# for sample in self.anchors:
# db = [r for r in self.samples[sample]['data'] if r['Session'] == session]
# if len(db):
# repl_kw['mec'] = anchor_color
# X = [r['d47'] for r in db]
# Y = [r['D47'] for r in db]
# ppl.plot(X, Y, **repl_kw)
#
# avg_kw['color'] = anchor_color
# X = [min(X)-.5, max(X)+.5]
# Y = [self.samples[sample]['D47']] * 2
# ppl.plot(X, Y, **avg_kw)
#
# outliers = [r for r in db if abs(r['D47'] - self.Nominal_D47[r['Sample']])>.1]
# for r in outliers:
# print(r['UID'], r['Sample'], r['D47'])
# X = [r['d47'] for r in outliers]
# Y = [r['D47'] for r in outliers]
# ppl.plot(X, Y, 'o', mfc = 'None', mec = (1,0,1), mew = 2)
#
# for sample in self.unknowns:
#
# db = [r for r in self.samples[sample]['data'] if r['Session'] == session]
# if len(db):
# repl_kw['mec'] = unknown_color
# X = [r['d47'] for r in db]
# Y = [r['D47'] for r in db]
# ppl.plot(X, Y, **repl_kw)
#
# avg_kw['color'] = unknown_color
# X = [min(X)-.19, max(X)+.19]
# Y = [self.samples[sample]['D47']] * 2
# ppl.plot(X, Y, **avg_kw)
#
# XI,YI = np.meshgrid(np.linspace(xmin, xmax), np.linspace(ymin, ymax))
# SI = np.array([[self.standardization_error(session, xi, yi) for xi in XI[0,:]] for yi in YI[:,0]])
# rng = np.max(SI) - np.min(SI)
# if rng <= 0.01:
# cinterval = 0.001
# elif rng <= 0.03:
# cinterval = 0.004
# elif rng <= 0.1:
# cinterval = 0.01
# elif rng <= 0.3:
# cinterval = 0.03
# else:
# cinterval = 0.1
# cval = [np.ceil(SI.min() / .001) * .001 + k * cinterval for k in range(int(np.ceil((SI.max() - SI.min()) / cinterval)))]
# cs = ppl.contour(XI, YI, SI, cval, colors = anchor_color, alpha = .5)
# ppl.clabel(cs)
#
# ppl.axis([xmin, xmax, ymin, ymax])
# ppl.xlabel('δ$_{47}$ (‰ WG)')
# ppl.ylabel('Δ$_{47}$ (‰)')
# ppl.grid(alpha = .15)
# ppl.title(session, weight = 'bold')
# ppl.savefig(f'{dir}/D47model_{session}.pdf')
# ppl.close(fig)
# def sample_D47_covar(self, sample_1, sample_2 = ''):
# '''
# Covariance between Δ47 values of samples
#
# Returns the covariance (or the variance, if sample_1 == sample_2)
# between the average Δ47 values of two samples. Also returns the
# variance if only sample_1 is specified.
# '''
# i = self.standardization.var_names.index(f'D47_{pf(sample_1)}')
# if sample_2 in [sample_1,'']:
# return self.standardization.covar[i,i]
# else:
# j = self.standardization.var_names.index(f'D47_{pf(sample_2)}')
# return self.standardization.covar[i,j]
#
@make_verbal
def consolidate_samples(self):
'''
Compile various statistics for each sample.
For each anchor sample:
+ `D47`: the nominal Δ<sub>47</sub> value for this anchor, specified by `self.Nominal_D47`
+ `SE_D47`: set to zero by definition
For each unknown sample:
+ `D47`: the standardized Δ<sub>47</sub> value for this unknown
+ `SE_D47`: the standard error of Δ<sub>47</sub> for this unknown
For each anchor and unknown:
+ `N`: the total number of analyses of this sample
+ `SD_D47`: the “sample” (in the statistical sense) standard deviation for this sample
+ `d13C_VPDB`: the average δ<sup>13</sup>C<sub>VPDB</sub> value for this sample
+ `d18O_VSMOW`: the average δ<sup>18</sup>O<sub>VSMOW</sub> value for this sample (as CO<sub>2</sub>)
+ `p_Levene`: the p-value from a [Levene test] of equal variance, indicating whether
the Δ<sub>47</sub> repeatability this sample differs significantly from that observed
for the reference sample specified by `self.LEVENE_REF_SAMPLE`.
[Levene test]: https://en.wikipedia.org/wiki/Levene%27s_test
'''
D47_ref_pop = [r['D47'] for r in self.samples[self.LEVENE_REF_SAMPLE]['data']]
for sample in self.samples:
self.samples[sample]['N'] = len(self.samples[sample]['data'])
if self.samples[sample]['N'] > 1:
self.samples[sample]['SD_D47'] = stdev([r['D47'] for r in self.samples[sample]['data']])
self.samples[sample]['d13C_VPDB'] = np.mean([r['d13C_VPDB'] for r in self.samples[sample]['data']])
self.samples[sample]['d18O_VSMOW'] = np.mean([r['d18O_VSMOW'] for r in self.samples[sample]['data']])
D47_pop = [r['D47'] for r in self.samples[sample]['data']]
if len(D47_pop) > 2:
self.samples[sample]['p_Levene'] = levene(D47_ref_pop, D47_pop, center = 'median')[1]
if self.standardization_method == 'pooled':
for sample in self.anchors:
self.samples[sample]['D47'] = self.Nominal_D47[sample]
self.samples[sample]['SE_D47'] = 0.
for sample in self.unknowns:
self.samples[sample]['D47'] = self.standardization.params.valuesdict()[f'D47_{pf(sample)}']
self.samples[sample]['SE_D47'] = self.sample_D47_covar(sample)**.5
elif self.standardization_method == 'indep_sessions':
for sample in self.anchors:
self.samples[sample]['D47'] = self.Nominal_D47[sample]
self.samples[sample]['SE_D47'] = 0.
for sample in self.unknowns:
self.msg(f'Consolidating sample {sample}')
self.unknowns[sample]['session_D47'] = {}
session_avg = []
for session in self.sessions:
sdata = [r for r in self.sessions[session]['data'] if r['Sample'] == sample]
if sdata:
self.msg(f'{sample} found in session {session}')
avg_D47 = np.mean([r['D47'] for r in sdata])
avg_d47 = np.mean([r['d47'] for r in sdata])
# !! TODO: sigma_s below does not account for temporal changes in standardization error
sigma_s = self.standardization_error(session, avg_d47, avg_D47)
sigma_u = sdata[0]['wD47raw'] / self.sessions[session]['a'] / len(sdata)**.5
session_avg.append([avg_D47, (sigma_u**2 + sigma_s**2)**.5])
self.unknowns[sample]['session_D47'][session] = session_avg[-1]
self.samples[sample]['D47'], self.samples[sample]['SE_D47'] = w_avg(*zip(*session_avg))
weights = {s: self.unknowns[sample]['session_D47'][s][1]**-2 for s in self.unknowns[sample]['session_D47']}
wsum = sum([weights[s] for s in weights])
for s in weights:
self.unknowns[sample]['session_D47'][s] += [self.unknowns[sample]['session_D47'][s][1]**-2 / wsum]
def consolidate_sessions(self):
'''
Compile various statistics for each session.
+ `Na`: Number of anchor analyses in the session
+ `Nu`: Number of unknown analyses in the session
+ `r_d13C_VPDB`: δ<sup>13</sup>C<sub>VPDB</sub> repeatability of analyses within the session
+ `r_d18O_VSMOW`: δ<sup>18</sup>O<sub>VSMOW</sub> repeatability of analyses within the session
+ `r_D47`: Δ<sub>47</sub> repeatability of analyses within the session
+ `a`: scrambling factor
+ `b`: compositional slope
+ `c`: WG offset
+ `SE_a`: Model stadard erorr of `a`
+ `SE_b`: Model stadard erorr of `b`
+ `SE_c`: Model stadard erorr of `c`
+ `scrambling_drift` (boolean): whether to allow a temporal drift in the scrambling factor (`a`)
+ `slope_drift` (boolean): whether to allow a temporal drift in the compositional slope (`b`)
+ `wg_drift` (boolean): whether to allow a temporal drift in the WG offset (`c`)
+ `a2`: scrambling factor drift
+ `b2`: compositional slope drift
+ `c2`: WG offset drift
+ `Np`: Number of standardization parameters to fit
+ `CM`: model covariance matrix for (`a`, `b`, `c`, `a2`, `b2`, `c2`)
+ `d13Cwg_VPDB`: δ<sup>13</sup>C<sub>VPDB</sub> of WG
+ `d18Owg_VSMOW`: δ<sup>18</sup>O<sub>VSMOW</sub> of WG
'''
for session in self.sessions:
if 'd13Cwg_VPDB' not in self.sessions[session]:
self.sessions[session]['d13Cwg_VPDB'] = self.sessions[session]['data'][0]['d13Cwg_VPDB']
if 'd18Owg_VSMOW' not in self.sessions[session]:
self.sessions[session]['d18Owg_VSMOW'] = self.sessions[session]['data'][0]['d18Owg_VSMOW']
self.sessions[session]['Na'] = len([r for r in self.sessions[session]['data'] if r['Sample'] in self.anchors])
self.sessions[session]['Nu'] = len([r for r in self.sessions[session]['data'] if r['Sample'] in self.unknowns])
self.msg(f'Computing repeatabilities for session {session}')
self.sessions[session]['r_d13C_VPDB'] = self.compute_r('d13C_VPDB', samples = 'anchors', sessions = [session])
self.sessions[session]['r_d18O_VSMOW'] = self.compute_r('d18O_VSMOW', samples = 'anchors', sessions = [session])
self.sessions[session]['r_D47'] = self.compute_r('D47', sessions = [session])
if self.standardization_method == 'pooled':
for session in self.sessions:
self.sessions[session]['Np'] = 3
for k in ['scrambling', 'slope', 'wg']:
if self.sessions[session][f'{k}_drift']:
self.sessions[session]['Np'] += 1
self.sessions[session]['a'] = self.standardization.params.valuesdict()[f'a_{pf(session)}']
i = self.standardization.var_names.index(f'a_{pf(session)}')
self.sessions[session]['SE_a'] = self.standardization.covar[i,i]**.5
self.sessions[session]['b'] = self.standardization.params.valuesdict()[f'b_{pf(session)}']
i = self.standardization.var_names.index(f'b_{pf(session)}')
self.sessions[session]['SE_b'] = self.standardization.covar[i,i]**.5
self.sessions[session]['c'] = self.standardization.params.valuesdict()[f'c_{pf(session)}']
i = self.standardization.var_names.index(f'c_{pf(session)}')
self.sessions[session]['SE_c'] = self.standardization.covar[i,i]**.5
self.sessions[session]['a2'] = self.standardization.params.valuesdict()[f'a2_{pf(session)}']
if self.sessions[session]['scrambling_drift']:
i = self.standardization.var_names.index(f'a2_{pf(session)}')
self.sessions[session]['SE_a2'] = self.standardization.covar[i,i]**.5
else:
self.sessions[session]['SE_a2'] = 0.
self.sessions[session]['b2'] = self.standardization.params.valuesdict()[f'b2_{pf(session)}']
if self.sessions[session]['slope_drift']:
i = self.standardization.var_names.index(f'b2_{pf(session)}')
self.sessions[session]['SE_b2'] = self.standardization.covar[i,i]**.5
else:
self.sessions[session]['SE_b2'] = 0.
self.sessions[session]['c2'] = self.standardization.params.valuesdict()[f'c2_{pf(session)}']
if self.sessions[session]['wg_drift']:
i = self.standardization.var_names.index(f'c2_{pf(session)}')
self.sessions[session]['SE_c2'] = self.standardization.covar[i,i]**.5
else:
self.sessions[session]['SE_c2'] = 0.
i = self.standardization.var_names.index(f'a_{pf(session)}')
j = self.standardization.var_names.index(f'b_{pf(session)}')
k = self.standardization.var_names.index(f'c_{pf(session)}')
CM = np.zeros((6,6))
CM[:3,:3] = self.standardization.covar[[i,j,k],:][:,[i,j,k]]
try:
i2 = self.standardization.var_names.index(f'a2_{pf(session)}')
CM[3,[0,1,2,3]] = self.standardization.covar[i2,[i,j,k,i2]]
CM[[0,1,2,3],3] = self.standardization.covar[[i,j,k,i2],i2]
try:
j2 = self.standardization.var_names.index(f'b2_{pf(session)}')
CM[3,4] = self.standardization.covar[i2,j2]
CM[4,3] = self.standardization.covar[j2,i2]
except ValueError:
pass
try:
k2 = self.standardization.var_names.index(f'c2_{pf(session)}')
CM[3,5] = self.standardization.covar[i2,k2]
CM[5,3] = self.standardization.covar[k2,i2]
except ValueError:
pass
except ValueError:
pass
try:
j2 = self.standardization.var_names.index(f'b2_{pf(session)}')
CM[4,[0,1,2,4]] = self.standardization.covar[j2,[i,j,k,j2]]
CM[[0,1,2,4],4] = self.standardization.covar[[i,j,k,j2],j2]
try:
k2 = self.standardization.var_names.index(f'c2_{pf(session)}')
CM[4,5] = self.standardization.covar[j2,k2]
CM[5,4] = self.standardization.covar[k2,j2]
except ValueError:
pass
except ValueError:
pass
try:
k2 = self.standardization.var_names.index(f'c2_{pf(session)}')
CM[5,[0,1,2,5]] = self.standardization.covar[k2,[i,j,k,k2]]
CM[[0,1,2,5],5] = self.standardization.covar[[i,j,k,k2],k2]
except ValueError:
pass
self.sessions[session]['CM'] = CM
elif self.standardization_method == 'indep_sessions':
pass
@make_verbal
def repeatabilies(self):
'''
Compute analytical repeatabilities for δ<sup>13</sup>C<sub>VPDB</sub>,
δ<sup>18</sup>O<sub>VSMOW</sub>, Δ<sub>47</sub> (for all samples, for anchors,
and for unknowns).
'''
self.msg('Computing reproducibilities for all sessions')
self.repeatability['r_d13C_VPDB'] = self.compute_r('d13C_VPDB', samples = 'anchors')
self.repeatability['r_d18O_VSMOW'] = self.compute_r('d18O_VSMOW', samples = 'anchors')
N_anchor_analyses = len([r for r in self if r['Sample'] in self.anchors])
self.repeatability['r_D47a'] = self.compute_r('D47', samples = 'anchors')
self.repeatability['r_D47a'] /= (
(N_anchor_analyses - np.sum([self.sessions[s]['Np'] for s in self.sessions])) / (N_anchor_analyses - len(self.anchors))
)**.5
self.repeatability['r_D47u'] = self.compute_r('D47', samples = 'unknowns')
self.repeatability['r_D47'] = self.compute_r('D47', samples = 'all samples')
self.repeatability['r_D47'] /= (
(len(self) - len(self.unknowns) - np.sum([self.sessions[s]['Np'] for s in self.sessions])) / (len(self) - len(self.samples))
)**.5
@make_verbal
def consolidate(self, tables = True, plots = True):
'''
Collect information about samples, sessions and repeatabilities.
'''
self.consolidate_samples()
self.consolidate_sessions()
self.repeatabilies()
if tables:
self.summary()
self.table_of_sessions()
self.table_of_analyses()
self.table_of_samples()
if plots:
self.plot_sessions()
@make_verbal
def rmswd(self,
samples = 'all samples',
sessions = 'all sessions',
):
'''
Compute the root mean squared weighted deviation, χ2 and
corresponding degrees of freedom of `[r['D47'] for r in self]`
'''
if samples == 'all samples':
mysamples = [k for k in self.samples]
elif samples == 'anchors':
mysamples = [k for k in self.anchors]
elif samples == 'unknowns':
mysamples = [k for k in self.unknowns]
else:
mysamples = samples
if sessions == 'all sessions':
sessions = [k for k in self.sessions]
chisq, Nf = 0, 0
for sample in mysamples :
G = [ r for r in self if r['Sample'] == sample and r['Session'] in sessions ]
if len(G) > 1 :
X, sX = w_avg([r['D47'] for r in G], [r['wD47'] for r in G])
Nf += (len(G) - 1)
chisq += np.sum([ ((r['D47']-X)/r['wD47'])**2 for r in G])
r = (chisq / Nf)**.5 if Nf > 0 else 0
self.msg(f'RMSWD of r["D47"] is {r:.6f} for {samples}.')
return {'rmswd': r, 'chisq': chisq, 'Nf': Nf}
@make_verbal
def compute_r(self, key, samples = 'all samples', sessions = 'all sessions'):
'''
Compute the repeatability of `[r[key] for r in self]`
'''
# NB: it's debatable whether rD47 should be computed
# with Nf = len(self)-len(self.samples) instead of
# Nf = len(self) - len(self.unknwons) - 3*len(self.sessions)
if samples == 'all samples':
mysamples = [k for k in self.samples]
elif samples == 'anchors':
mysamples = [k for k in self.anchors]
elif samples == 'unknowns':
mysamples = [k for k in self.unknowns]
else:
mysamples = samples
if sessions == 'all sessions':
sessions = [k for k in self.sessions]
chisq, Nf = 0, 0
for sample in mysamples :
X = [ r[key] for r in self if r['Sample'] == sample and r['Session'] in sessions ]
if len(X) > 1 :
Nf += len(X) - 1
chisq += np.sum([ (x-np.mean(X))**2 for x in X ])
r = (chisq / Nf)**.5 if Nf > 0 else 0
self.msg(f'Repeatability of r["{key}"] is {1000*r:.1f} ppm for {samples}.')
return r
def sample_average(self, samples, weights = 'equal', normalize = True):
'''
Weighted average Δ<sub>47</sub> value of a group of samples, accounting for covariance.
Returns the weighed average Δ47 value and associated SE
of a group of samples. Weights are equal by default. If `normalize` is
true, `weights` will be rescaled so that their sum equals 1.
__Examples__
```python
self.sample_average(['X','Y'], [1, 2])
```
returns the value and SE of [Δ<sub>47</sub>(X) + 2 Δ<sub>47</sub>(Y)]/3,
where Δ<sub>47</sub>(X) and Δ<sub>47</sub>(Y) are the average Δ<sub>47</sub>
values of samples X and Y, respectively.
```python
self.sample_average(['X','Y'], [1, -1], normalize = False)
```
returns the value and SE of the difference Δ<sub>47</sub>(X) - Δ<sub>47</sub>(Y).
'''
if weights == 'equal':
weights = [1/len(samples)] * len(samples)
if normalize:
s = sum(weights)
weights = [w/s for w in weights]
try:
# indices = [self.standardization.var_names.index(f'D47_{pf(sample)}') for sample in samples]
# C = self.standardization.covar[indices,:][:,indices]
C = np.array([[self.sample_D47_covar(x, y) for x in samples] for y in samples])
X = [self.samples[sample]['D47'] for sample in samples]
return correlated_sum(X, C, weights)
except ValueError:
return (0., 0.)
def sample_D47_covar(self, sample1, sample2 = ''):
'''
Covariance between Δ<sub>47</sub> values of samples
Returns the error covariance between the average Δ<sub>47</sub> values of two
samples. If if only `sample_1` is specified, or if `sample_1 == sample_2`),
returns the Δ<sub>47</sub> variance for that sample.
'''
if sample2 == '':
sample2 = sample1
if self.standardization_method == 'pooled':
i = self.standardization.var_names.index(f'D47_{pf(sample1)}')
j = self.standardization.var_names.index(f'D47_{pf(sample2)}')
return self.standardization.covar[i, j]
elif self.standardization_method == 'indep_sessions':
if sample1 == sample2:
return self.samples[sample1]['SE_D47']**2
else:
c = 0
for session in self.sessions:
sdata1 = [r for r in self.sessions[session]['data'] if r['Sample'] == sample1]
sdata2 = [r for r in self.sessions[session]['data'] if r['Sample'] == sample2]
if sdata1 and sdata2:
a = self.sessions[session]['a']
# !! TODO: CM below does not account for temporal changes in standardization parameters
CM = self.sessions[session]['CM'][:3,:3]
avg_D47_1 = np.mean([r['D47'] for r in sdata1])
avg_d47_1 = np.mean([r['d47'] for r in sdata1])
avg_D47_2 = np.mean([r['D47'] for r in sdata2])
avg_d47_2 = np.mean([r['d47'] for r in sdata2])
c += (
self.unknowns[sample1]['session_D47'][session][2]
* self.unknowns[sample2]['session_D47'][session][2]
* np.array([[avg_D47_1, avg_d47_1, 1]])
@ CM
@ np.array([[avg_D47_2, avg_d47_2, 1]]).T
) / a**2
return float(c)
def sample_D47_correl(self, sample1, sample2 = ''):
'''
Correlation between Δ<sub>47</sub> errors of samples
Returns the error correlation between the average Δ47 values of two samples.
'''
if sample2 == '' or sample2 == sample1:
return 1.
return (
self.sample_D47_covar(sample1, sample2)
/ self.unknowns[sample1]['SE_D47']
/ self.unknowns[sample2]['SE_D47']
)
def plot_single_session(self,
session,
kw_plot_anchors = dict(ls='None', marker='x', mec=(.75, 0, 0), mew = .75, ms = 4),
kw_plot_unknowns = dict(ls='None', marker='x', mec=(0, 0, .75), mew = .75, ms = 4),
kw_plot_anchor_avg = dict(ls='-', marker='None', color=(.75, 0, 0), lw = .75),
kw_plot_unknown_avg = dict(ls='-', marker='None', color=(0, 0, .75), lw = .75),
kw_contour_error = dict(colors = [[0, 0, 0]], alpha = .5, linewidths = 0.75),
xylimits = 'free', # | 'constant'
x_label = 'δ$_{47}$ (‰)',
y_label = 'Δ$_{47}$ (‰)',
error_contour_interval = 'auto',
fig = 'new',
):
'''
Generate plot for a single session
'''
out = SessionPlot()
if fig == 'new':
out.fig = ppl.figure(figsize = (6,6))
ppl.subplots_adjust(.1,.1,.9,.9)
out.anchor_analyses, = ppl.plot(
[r['d47'] for r in self.sessions[session]['data'] if r['Sample'] in self.anchors],
[r['D47'] for r in self.sessions[session]['data'] if r['Sample'] in self.anchors],
**kw_plot_anchors)
out.unknown_analyses, = ppl.plot(
[r['d47'] for r in self.sessions[session]['data'] if r['Sample'] in self.unknowns],
[r['D47'] for r in self.sessions[session]['data'] if r['Sample'] in self.unknowns],
**kw_plot_unknowns)
out.anchor_avg = ppl.plot(
np.array([ np.array([-.5, .5]) + np.mean([r['d47'] for r in self.sessions[session]['data'] if r['Sample'] == sample]) for sample in self.anchors]).T,
np.array([ np.array([0, 0]) + self.Nominal_D47[sample] for sample in self.anchors]).T,
'-', **kw_plot_anchor_avg)
out.unknown_avg = ppl.plot(
np.array([ np.array([-.5, .5]) + np.mean([r['d47'] for r in self.sessions[session]['data'] if r['Sample'] == sample]) for sample in self.unknowns]).T,
np.array([ np.array([0, 0]) + self.unknowns[sample]['D47'] for sample in self.unknowns]).T,
'-', **kw_plot_unknown_avg)
if xylimits == 'constant':
x = [r['d47'] for r in self]
y = [r['D47'] for r in self]
x1, x2, y1, y2 = np.min(x), np.max(x), np.min(y), np.max(y)
w, h = x2-x1, y2-y1
x1 -= w/20
x2 += w/20
y1 -= h/20
y2 += h/20
ppl.axis([x1, x2, y1, y2])
elif xylimits != 'free':
x1, x2, y1, y2 = ppl.axis()
else:
x1, x2, y1, y2 = ppl.axis(xylimits)
if error_contour_interval != 'none':
xi, yi = np.linspace(x1, x2), np.linspace(y1, y2)
XI,YI = np.meshgrid(xi, yi)
SI = np.array([[self.standardization_error(session, x, y) for x in xi] for y in yi])
if error_contour_interval == 'auto':
rng = np.max(SI) - np.min(SI)
if rng <= 0.01:
cinterval = 0.001
elif rng <= 0.03:
cinterval = 0.004
elif rng <= 0.1:
cinterval = 0.01
elif rng <= 0.3:
cinterval = 0.03
elif rng <= 1.:
cinterval = 0.1
else:
cinterval = 0.5
else:
cinterval = error_contour_interval
cval = np.arange(np.ceil(SI.min() / .001) * .001, np.ceil(SI.max() / .001 + 1) * .001, cinterval)
out.contour = ppl.contour(XI, YI, SI, cval, **kw_contour_error)
out.clabel = ppl.clabel(out.contour)
ppl.xlabel(x_label)
ppl.ylabel(y_label)
ppl.title(session, weight = 'bold')
ppl.grid(alpha = .2)
out.ax = ppl.gca()
return out
class SessionPlot():
def __init__(self):
pass
# rng = np.max(SI) - np.min(SI)
# if rng <= 0.01:
# cinterval = 0.001
# elif rng <= 0.03:
# cinterval = 0.004
# elif rng <= 0.1:
# cinterval = 0.01
# elif rng <= 0.3:
# cinterval = 0.03
# else:
# cinterval = 0.1Functions
-
Compute covariance-aware linear combinations
Return the mean and SE of the sum of the elements of
X, with optional weights corresponding to the elements off, accounting forC, the covariance matrix ofX.Expand source code
def correlated_sum(X,C,f = ''): ''' Compute covariance-aware linear combinations Return the mean and SE of the sum of the elements of `X`, with optional weights corresponding to the elements of `f`, accounting for `C`, the covariance matrix of `X`. ''' if f == '': f = [1 for x in X] return np.dot(f,X), (np.dot(f,np.dot(C,f)))**.5 def fCO2eqD47_Petersen(T)-
CO2 equilibrium Δ47 value as a function of
T(in degrees C) according to Petersen et al. (2019).Expand source code
def fCO2eqD47_Petersen(T): ''' CO<sub>2</sub> equilibrium Δ<sub>47</sub> value as a function of `T` (in degrees C) according to [Petersen et al. (2019)]. [Petersen et al. (2019)]: https://doi.org/10.1029/2018GC008127 ''' return float(_fCO2eqD47_Petersen(T)) def fCO2eqD47_Wang(T)-
CO2 equilibrium Δ47 value as a function of
T(in degrees C) according to Wang et al. (2004) (supplementary data of Dennis et al., 2011).Expand source code
def fCO2eqD47_Wang(T): ''' CO<sub>2</sub> equilibrium Δ<sub>47</sub> value as a function of `T` (in degrees C) according to [Wang et al. (2004)] (supplementary data of [Dennis et al., 2011]). [Wang et al. (2004)]: https://doi.org/10.1016/j.gca.2004.05.039 [Dennis et al., 2011]: https://doi.org/10.1016/j.gca.2011.09.025 ''' return float(_fCO2eqD47_Wang(T)) def make_csv(x, hsep=',', vsep='\n')-
Formats a list of lists of strings as a CSV
Parameters
x: the list of lists of strings to formathsep: the field separator (a comma, by default)vsep: the line-ending convention to use ('\n'by default)
Example
x = [['a', 'b', 'c'], ['d', 'e', 'f']] print(make_csv(x))output:
a,b,c d,e,fExpand source code
def make_csv(x, hsep = ',', vsep = '\n'): ''' Formats a list of lists of strings as a CSV __Parameters__ + `x`: the list of lists of strings to format + `hsep`: the field separator (a comma, by default) + `vsep`: the line-ending convention to use (`'\\n'` by default) __Example__ ```python x = [['a', 'b', 'c'], ['d', 'e', 'f']] print(make_csv(x)) ``` output: ```python a,b,c d,e,f ``` ''' return vsep.join([hsep.join(l) for l in x]) def pf(txt)-
Modify string
txtto followlmfit.Parameter()naming rules.Expand source code
def pf(txt): ''' Modify string `txt` to follow `lmfit.Parameter()` naming rules. ''' return txt.replace('-','_').replace('.','_').replace(' ','_') def pretty_table(x, header=1, hsep=' ', vsep='–', align='<')-
Reads a list of lists of strings and outputs an ascii table
Parameters
x: a list of lists of stringsheader: the number of lines to treat as header lineshsep: the horizontal separator between columnsvsep: the character to use as vertical separatoralign: string of left (<) or right (>) alignment characters.
Example
x = [['A','B', 'C'], ['1', '1.9999', 'foo'], ['10', 'x', 'bar']] print(pretty_table(x))output:
-- ------ --- A B C -- ------ --- 1 1.9999 foo 10 x bar -- ------ ---Expand source code
def pretty_table(x, header = 1, hsep = ' ', vsep = '–', align = '<'): ''' Reads a list of lists of strings and outputs an ascii table __Parameters__ + `x`: a list of lists of strings + `header`: the number of lines to treat as header lines + `hsep`: the horizontal separator between columns + `vsep`: the character to use as vertical separator + `align`: string of left (`<`) or right (`>`) alignment characters. __Example__ ```python x = [['A','B', 'C'], ['1', '1.9999', 'foo'], ['10', 'x', 'bar']] print(pretty_table(x)) ``` output: ```python -- ------ --- A B C -- ------ --- 1 1.9999 foo 10 x bar -- ------ --- ``` ''' txt = [] widths = [np.max([len(e) for e in c]) for c in zip(*x)] if len(widths) > len(align): align += '>' * (len(widths)-len(align)) sepline = hsep.join([vsep*w for w in widths]) txt += [sepline] for k,l in enumerate(x): if k and k == header: txt += [sepline] txt += [hsep.join([f'{e:{a}{w}}' for e, w, a in zip(l, widths, align)])] txt += [sepline] txt += [''] return '\n'.join(txt) def smart_type(x)-
Tries to convert string
xto a float if it includes a decimal point, or to an integer if it does not. If both attempts fail, return the original string unchanged.Expand source code
def smart_type(x): ''' Tries to convert string `x` to a float if it includes a decimal point, or to an integer if it does not. If both attempts fail, return the original string unchanged. ''' try: y = float(x) except ValueError: return x if '.' not in x: return int(y) return y def transpose_table(x)-
Transpose a list if lists
Parameters
x: a list of lists
Example
x = [[1, 2], [3, 4]] print(transpose_table(x))outputs:
[[1, 3], [2, 4]]Expand source code
def transpose_table(x): ''' Transpose a list if lists __Parameters__ + `x`: a list of lists __Example__ ```python x = [[1, 2], [3, 4]] print(transpose_table(x)) ``` outputs: ```python [[1, 3], [2, 4]] ``` ''' return [[e for e in c] for c in zip(*x)] def w_avg(X, sX)-
Compute variance-weighted average
Returns the value and SE of the weighted average of the elements of
X, with relative weights equal to their inverse variances (1/sX**2).Parameters
X: array-like of elements to averagesX: array-like of the corresponding SE values
Tip
If
XandsXare initially arranged as a list of(x, sx)doublets, they may be rearranged usingzip():foo = [(0, 0.1), (1, 0.05), (2, 0.05)] print(w_avg(*zip(*foo))) # output: # (1.3333333333333333, 0.03333333333333334)Expand source code
def w_avg(X, sX) : ''' Compute variance-weighted average Returns the value and SE of the weighted average of the elements of `X`, with relative weights equal to their inverse variances (`1/sX**2`). __Parameters__ + `X`: array-like of elements to average + `sX`: array-like of the corresponding SE values __Tip__ If `X` and `sX` are initially arranged as a list of `(x, sx)` doublets, they may be rearranged using `zip()`: ```python foo = [(0, 0.1), (1, 0.05), (2, 0.05)] print(w_avg(*zip(*foo))) # output: # (1.3333333333333333, 0.03333333333333334) ``` ''' X = [ x for x in X ] sX = [ sx for sx in sX ] W = [ sx**-2 for sx in sX ] W = [ w/sum(W) for w in W ] Xavg = sum([ w*x for w,x in zip(W,X) ]) sXavg = sum([ w**2*sx**2 for w,sx in zip(W,sX) ])**.5 return Xavg, sXavg
Classes
class D47data (l=[], logfile='', session='mySession', verbose=False)-
Store and process data for a large set of Δ47 analyses, usually comprising more than one analytical session.
Parameters
l: a list of dictionaries, with each dictionary including at least the keysSample,d45,d46, andd47.logfile: if specified, write detailed logs to this file path when callingD47datamethods.session: define session name for analyses without aSessionkeyverbose: ifTrue, print out detailed logs when callingD47datamethods.
Returns a
D47dataobject derived fromlist.Expand source code
class D47data(list): ''' Store and process data for a large set of Δ<sub>47</sub> analyses, usually comprising more than one analytical session. ''' ### 17O CORRECTION PARAMETERS R13_VPDB = 0.01118 # (Chang & Li, 1990) ''' Absolute (<sup>13</sup>C/<sup>12</sup>C) ratio of VPDB. By default equal to 0.01118 ([Chang & Li, 1990]) [Chang & Li, 1990]: http://www.cnki.com.cn/Article/CJFDTotal-JXTW199004006.htm ''' R18_VSMOW = 0.0020052 # (Baertschi, 1976) ''' Absolute (<sup>18</sup>O/<sup>16</sup>C) ratio of VSMOW. By default equal to 0.0020052 ([Baertschi, 1976]) [Baertschi, 1976]: https://doi.org/10.1016/0012-821X(76)90115-1 ''' lambda_17 = 0.528 # (Barkan & Luz, 2005) ''' Mass-dependent exponent for triple oxygen isotopes. By default equal to 0.528 ([Barkan & Luz, 2005]) [Barkan & Luz, 2005]: https://doi.org/10.1002/rcm.2250 ''' R17_VSMOW = 0.00038475 # (Assonov & Brenninkmeijer, 2003, rescaled to R13_VPDB) ''' Absolute (<sup>17</sup>O/<sup>16</sup>C) ratio of VSMOW. By default equal to 0.00038475 ([Assonov & Brenninkmeijer, 2003], rescaled to `R13_VPDB`) [Assonov & Brenninkmeijer, 2003]: https://dx.doi.org/10.1002/rcm.1011 ''' R18_VPDB = R18_VSMOW * 1.03092 ''' Absolute (<sup>18</sup>O/<sup>16</sup>C) ratio of VPDB. By definition equal to `R18_VSMOW * 1.03092`. ''' R17_VPDB = R17_VSMOW * 1.03092 ** lambda_17 ''' Absolute (<sup>17</sup>O/<sup>16</sup>C) ratio of VPDB. By definition equal to `R17_VSMOW * 1.03092 ** lambda_17`. ''' LEVENE_REF_SAMPLE = 'ETH-3' ''' After the Δ<sub>47</sub> standardization step, each sample is tested to assess whether the Δ<sub>47</sub> variance within all analyses for that sample differs significantly from that observed for a given reference sample (using [Levene's test], which yields a p-value corresponding to the null hypothesis that the underlying variances are equal). `LEVENE_REF_SAMPLE` (by default equal to `'ETH-3'`) specifies which sample should be used as a reference for this test. [Levene's test]: https://en.wikipedia.org/wiki/Levene%27s_test ''' SAMPLE_CONSTRAINING_WG_COMPOSITION = ('ETH-3', 1.71, -1.78) # (Bernasconi et al., 2018) ''' Specifies the name, δ<sup>13</sup>C<sub>VPDB</sub> and δ<sup>18</sup>O<sub>VPDB</sub> of the carbonate standard used by `D47data.wg()` to compute the isotopic composition of the working gas in each session. By default equal to `('ETH-3', 1.71, -1.78)` after [Bernasconi et al. (2018)]. [Bernasconi et al. (2018)]: https://doi.org/10.1029/2017GC007385 ''' ALPHA_18O_ACID_REACTION = round(np.exp(3.59 / (90 + 273.15) - 1.79e-3), 6) # (Kim et al., 2007, calcite) ''' Specifies the <sup>18</sup>O/<sup>16</sup>O fractionation factor generally applicable to acid reactions in the dataset. Currently used by `D47data.wg()`, `D47data.standardize_d13C`, and `D47data.standardize_d18O`. By default equal to 1.008129 (calcite reacted at 90 °C, [Kim et al., 2007]). [Kim et al., 2007]: https://dx.doi.org/10.1016/j.chemgeo.2007.08.005 ''' Nominal_D47 = { 'ETH-1': 0.258, 'ETH-2': 0.256, 'ETH-3': 0.691, } # (Bernasconi et al., 2018) ''' Nominal Δ<sub>47</sub> values assigned to the anchor samples, used by `D47data.standardize()` to standardize unknown samples to an absolute Δ<sub>47</sub> reference frame. By default equal to `{'ETH-1': 0.258, 'ETH-2': 0.256, 'ETH-3': 0.691}` after [Bernasconi et al. (2018)]. [Bernasconi et al. (2018)]: https://doi.org/10.1029/2017GC007385 ''' Nominal_d13C_VPDB = { 'ETH-1': 2.02, 'ETH-2': -10.17, 'ETH-3': 1.71, } # (Bernasconi et al., 2018) ''' Nominal δ<sup>13</sup>C<sub>VPDB</sub> values assigned to carbonate standards, used by `D47data.standardize_d13C()`. By default equal to `{'ETH-1': 2.02, 'ETH-2': -10.17, 'ETH-3': 1.71}` after [Bernasconi et al. (2018)]. [Bernasconi et al. (2018)]: https://doi.org/10.1029/2017GC007385 ''' Nominal_d18O_VPDB = { 'ETH-1': -2.19, 'ETH-2': -18.69, 'ETH-3': -1.78, } # (Bernasconi et al., 2018) ''' Nominal δ<sup>18</sup>O<sub>VPDB</sub> values assigned to carbonate standards, used by `D47data.standardize_d18O()`. By default equal to `{'ETH-1': -2.19, 'ETH-2': -18.69, 'ETH-3': -1.78}` after [Bernasconi et al. (2018)]. [Bernasconi et al. (2018)]: https://doi.org/10.1029/2017GC007385 ''' d13C_STANDARDIZATION_METHOD = '2pt' ''' Method by which to standardize δ<sup>13</sup>C values: + `none`: do not apply any δ<sup>13</sup>C standardization. + `'1pt'`: within each session, offset all initial δ<sup>13</sup>C values so as to minimize the difference between final δ<sup>13</sup>C<sub>VPDB</sub> values and `Nominal_d13C_VPDB` (averaged over all analyses for which `Nominal_d13C_VPDB` is defined). + `'2pt'`: within each session, apply a affine trasformation to all δ<sup>13</sup>C values so as to minimize the difference between final δ<sup>13</sup>C<sub>VPDB</sub> values and `Nominal_d13C_VPDB` (averaged over all analyses for which `Nominal_d13C_VPDB` is defined). ''' d18O_STANDARDIZATION_METHOD = '2pt' ''' Method by which to standardize δ<sup>18</sup>O values: + `none`: do not apply any δ<sup>18</sup>O standardization. + `'1pt'`: within each session, offset all initial δ<sup>18</sup>O values so as to minimize the difference between final δ<sup>18</sup>O<sub>VPDB</sub> values and `Nominal_d18O_VPDB` (averaged over all analyses for which `Nominal_d18O_VPDB` is defined). + `'2pt'`: within each session, apply a affine trasformation to all δ<sup>18</sup>O values so as to minimize the difference between final δ<sup>18</sup>O<sub>VPDB</sub> values and `Nominal_d18O_VPDB` (averaged over all analyses for which `Nominal_d18O_VPDB` is defined). ''' def __init__(self, l = [], logfile = '', session = 'mySession', verbose = False): ''' __Parameters__ + `l`: a list of dictionaries, with each dictionary including at least the keys `Sample`, `d45`, `d46`, and `d47`. + `logfile`: if specified, write detailed logs to this file path when calling `D47data` methods. + `session`: define session name for analyses without a `Session` key + `verbose`: if `True`, print out detailed logs when calling `D47data` methods. Returns a `D47data` object derived from `list`. ''' self.verbose = verbose self.prefix = 'D47data' self.logfile = logfile list.__init__(self, l) self.Nf = None self.repeatability = {} self.refresh(session = session) def make_verbal(oldfun): ''' Decorator to temporarily change `self.prefix` and allow locally overriding `self.verbose` ''' @wraps(oldfun) def newfun(*args, verbose = '', **kwargs): myself = args[0] oldprefix = myself.prefix myself.prefix = oldfun.__name__ if verbose != '': oldverbose = myself.verbose myself.verbose = verbose out = oldfun(*args, **kwargs) myself.prefix = oldprefix if verbose != '': myself.verbose = oldverbose return out return newfun def msg(self, txt): ''' Log a message to `self.logfile`, and print it out if `verbose = True` ''' self.log(txt) if self.verbose: print(f'{f"[{self.prefix}]":<16} {txt}') def vmsg(self, txt): ''' Log a message to `self.logfile` and print it out ''' self.log(txt) print(txt) def log(self, *txts): ''' Log a message to `self.logfile` ''' if self.logfile: with open(self.logfile, 'a') as fid: for txt in txts: fid.write(f'\n{dt.now().strftime("%Y-%m-%d %H:%M:%S")} {f"[{self.prefix}]":<16} {txt}') def refresh(self, session = 'mySession'): ''' Update `self.sessions`, `self.samples`, `self.anchors`, and `self.unknowns`. ''' self.fill_in_missing_info(session = session) self.refresh_sessions() self.refresh_samples() def refresh_sessions(self): ''' Update `self.sessions` and set `scrambling_drift`, `slope_drift`, and `wg_drift` to `False` for all sessions. ''' self.sessions = { s: {'data': [r for r in self if r['Session'] == s]} for s in sorted({r['Session'] for r in self}) } for s in self.sessions: self.sessions[s]['scrambling_drift'] = False self.sessions[s]['slope_drift'] = False self.sessions[s]['wg_drift'] = False self.sessions[s]['d13C_standardization_method'] = self.d13C_STANDARDIZATION_METHOD self.sessions[s]['d18O_standardization_method'] = self.d18O_STANDARDIZATION_METHOD def refresh_samples(self): ''' Define `self.samples`, `self.anchors`, and `self.unknowns`. ''' self.samples = { s: {'data': [r for r in self if r['Sample'] == s]} for s in sorted({r['Sample'] for r in self}) } self.anchors = {s: self.samples[s] for s in self.samples if s in self.Nominal_D47} self.unknowns = {s: self.samples[s] for s in self.samples if s not in self.Nominal_D47} def read(self, filename, sep = '', session = ''): ''' Read file in csv format to load data into a `D47data` object. In the csv file, spaces befor and after field separators (`','` by default) are optional. Each line corresponds to a single analysis. The required fields are: + `UID`: a unique identifier + `Session`: an identifier for the analytical session + `Sample`: a sample identifier + `d45`, `d46`, `d47`: the working-gas delta values Independently known oxygen-17 anomalies may be provided as `D17O` (in ‰ relative to VSMOW, λ = `self.lambda_17`), and are otherwise assumed to be zero. Working-gas deltas `d48` and `d49` may also be provided, and are also set to 0 otherwise. __Parameters__ + `fileneme`: the path of the file to read + `sep`: csv separator delimiting the fields + `session`: set `Session` field to this string for all analyses ''' with open(filename) as fid: self.input(fid.read(), sep = sep, session = session) def input(self, txt, sep = '', session = ''): ''' Read `txt` string in csv format to load analysis data into a `D47data` object. In the csv string, spaces befor and after field separators (`','` by default) are optional. Each line corresponds to a single analysis. The required fields are: + `UID`: a unique identifier + `Session`: an identifier for the analytical session + `Sample`: a sample identifier + `d45`, `d46`, `d47`: the working-gas delta values Independently known oxygen-17 anomalies may be provided as `D17O` (in ‰ relative to VSMOW, λ = `self.lambda_17`), and are otherwise assumed to be zero. Working-gas deltas `d48` and `d49` may also be provided, and are also set to 0 otherwise. __Parameters__ + `txt`: the csv string to read + `sep`: csv separator delimiting the fields. By default, use `,`, `;`, or `\t`, whichever appers most often in `txt`. + `session`: set `Session` field to this string for all analyses ''' if sep == '': sep = sorted(',;\t', key = lambda x: - txt.count(x))[0] txt = [[x.strip() for x in l.split(sep)] for l in txt.splitlines() if l.strip()] data = [{k: v if k in ['UID', 'Session', 'Sample'] else smart_type(v) for k,v in zip(txt[0], l)} for l in txt[1:]] if session != '': for r in data: r['Session'] = session self += data self.refresh() @make_verbal def wg(self, samples = '', a18_acid = ''): ''' Compute bulk composition of the working gas for each session based on the carbonate standards defined both in `self.Nominal_d13C_VPDB` and in `self.Nominal_d18O_VPDB`. ''' self.msg('Computing WG composition:') if a18_acid == '': a18_acid = self.ALPHA_18O_ACID_REACTION if samples == '': samples = [s for s in self.Nominal_d13C_VPDB if s in self.Nominal_d18O_VPDB] assert a18_acid, f'Acid fractionation value should differ from zero.' samples = [s for s in samples if s in self.Nominal_d13C_VPDB and s in self.Nominal_d18O_VPDB] R45R46_standards = {} for sample in samples: d13C_vpdb = self.Nominal_d13C_VPDB[sample] d18O_vpdb = self.Nominal_d18O_VPDB[sample] R13_s = self.R13_VPDB * (1 + d13C_vpdb / 1000) R17_s = self.R17_VPDB * ((1 + d18O_vpdb / 1000) * a18_acid) ** self.lambda_17 R18_s = self.R18_VPDB * (1 + d18O_vpdb / 1000) * a18_acid C12_s = 1 / (1 + R13_s) C13_s = R13_s / (1 + R13_s) C16_s = 1 / (1 + R17_s + R18_s) C17_s = R17_s / (1 + R17_s + R18_s) C18_s = R18_s / (1 + R17_s + R18_s) C626_s = C12_s * C16_s ** 2 C627_s = 2 * C12_s * C16_s * C17_s C628_s = 2 * C12_s * C16_s * C18_s C636_s = C13_s * C16_s ** 2 C637_s = 2 * C13_s * C16_s * C17_s C727_s = C12_s * C17_s ** 2 R45_s = (C627_s + C636_s) / C626_s R46_s = (C628_s + C637_s + C727_s) / C626_s R45R46_standards[sample] = (R45_s, R46_s) for s in self.sessions: db = [r for r in self.sessions[s]['data'] if r['Sample'] in samples] assert db, f'No sample from {samples} found in session "{s}".' # dbsamples = sorted({r['Sample'] for r in db}) X = [r['d45'] for r in db] Y = [R45R46_standards[r['Sample']][0] for r in db] x1, x2 = np.min(X), np.max(X) wgcoord = x1/(x1-x2) if wgcoord < -.5 or wgcoord > 1.5: # unreasonable to extrapolate to d45 = 0 R45_wg = np.mean([y/(1+x/1000) for x,y in zip(X,Y)]) else : # d45 = 0 is reasonably well bracketed R45_wg = np.polyfit(X, Y, 1)[1] X = [r['d46'] for r in db] Y = [R45R46_standards[r['Sample']][1] for r in db] x1, x2 = np.min(X), np.max(X) wgcoord = x1/(x1-x2) if wgcoord < -.5 or wgcoord > 1.5: # unreasonable to extrapolate to d46 = 0 R46_wg = np.mean([y/(1+x/1000) for x,y in zip(X,Y)]) else : # d46 = 0 is reasonably well bracketed R46_wg = np.polyfit(X, Y, 1)[1] d13Cwg_VPDB, d18Owg_VSMOW = self.compute_bulk_delta(R45_wg, R46_wg) self.msg(f'Session {s} WG: δ13C_VPDB = {d13Cwg_VPDB:.3f} δ18O_VSMOW = {d18Owg_VSMOW:.3f}') self.sessions[s]['d13Cwg_VPDB'] = d13Cwg_VPDB self.sessions[s]['d18Owg_VSMOW'] = d18Owg_VSMOW for r in self.sessions[s]['data']: r['d13Cwg_VPDB'] = d13Cwg_VPDB r['d18Owg_VSMOW'] = d18Owg_VSMOW @make_verbal def wg_old(self, sample = '', d13C_vpdb = '', d18O_vpdb = '', a18_acid = ''): ''' Compute bulk composition of the working gas for each session based on the average composition, within each session, of a given sample. ''' self.msg('Computing WG composition:') if sample == '': sample = self.SAMPLE_CONSTRAINING_WG_COMPOSITION[0] if d13C_vpdb == '': d13C_vpdb = self.SAMPLE_CONSTRAINING_WG_COMPOSITION[1] if d18O_vpdb == '': d18O_vpdb = self.SAMPLE_CONSTRAINING_WG_COMPOSITION[2] if a18_acid == '': a18_acid = self.ALPHA_18O_ACID_REACTION assert a18_acid, f'Acid fractionation value should differ from zero.' R13_s = self.R13_VPDB * (1 + d13C_vpdb / 1000) R17_s = self.R17_VPDB * ((1 + d18O_vpdb / 1000) * a18_acid) ** self.lambda_17 R18_s = self.R18_VPDB * (1 + d18O_vpdb / 1000) * a18_acid C12_s = 1 / (1 + R13_s) C13_s = R13_s / (1 + R13_s) C16_s = 1 / (1 + R17_s + R18_s) C17_s = R17_s / (1 + R17_s + R18_s) C18_s = R18_s / (1 + R17_s + R18_s) C626_s = C12_s * C16_s ** 2 C627_s = 2 * C12_s * C16_s * C17_s C628_s = 2 * C12_s * C16_s * C18_s C636_s = C13_s * C16_s ** 2 C637_s = 2 * C13_s * C16_s * C17_s C727_s = C12_s * C17_s ** 2 R45_s = (C627_s + C636_s) / C626_s R46_s = (C628_s + C637_s + C727_s) / C626_s for s in self.sessions: db = [r for r in self.sessions[s]['data'] if r['Sample'] == sample] assert db, f'Sample "{sample}" not found in session "{s}".' d45_s = np.mean([r['d45'] for r in db]) d46_s = np.mean([r['d46'] for r in db]) R45_wg = R45_s / (1 + d45_s / 1000) R46_wg = R46_s / (1 + d46_s / 1000) d13Cwg_VPDB, d18Owg_VSMOW = self.compute_bulk_delta(R45_wg, R46_wg) self.msg(f'Session {s} WG: δ13C_VPDB = {d13Cwg_VPDB:.3f} δ18O_VSMOW = {d18Owg_VSMOW:.3f}') self.sessions[s]['d13Cwg_VPDB'] = d13Cwg_VPDB self.sessions[s]['d18Owg_VSMOW'] = d18Owg_VSMOW for r in self.sessions[s]['data']: r['d13Cwg_VPDB'] = d13Cwg_VPDB r['d18Owg_VSMOW'] = d18Owg_VSMOW def compute_bulk_delta(self, R45, R46, D17O = 0): ''' Compute δ<sup>13</sup>C<sub>VPDB</sub> and δ<sup>18</sup>O<sub>VSMOW</sub>, by solving the generalized form of equation (17) from [Brand et al. (2010)], assuming that δ<sup>18</sup>O<sub>VSMOW</sub> is not too big (0 ± 50 ‰) and solving the corresponding second-order Taylor polynomial. (Appendix A of [Daëron et al., 2016]) [Brand et al. (2010)]: https://doi.org/10.1351/PAC-REP-09-01-05 [Daëron et al., 2016]: https://doi.org/10.1016/j.chemgeo.2016.08.014 ''' K = np.exp(D17O / 1000) * self.R17_VSMOW * self.R18_VSMOW ** -self.lambda_17 A = -3 * K ** 2 * self.R18_VSMOW ** (2 * self.lambda_17) B = 2 * K * R45 * self.R18_VSMOW ** self.lambda_17 C = 2 * self.R18_VSMOW D = -R46 aa = A * self.lambda_17 * (2 * self.lambda_17 - 1) + B * self.lambda_17 * (self.lambda_17 - 1) / 2 bb = 2 * A * self.lambda_17 + B * self.lambda_17 + C cc = A + B + C + D d18O_VSMOW = 1000 * (-bb + (bb ** 2 - 4 * aa * cc) ** .5) / (2 * aa) R18 = (1 + d18O_VSMOW / 1000) * self.R18_VSMOW R17 = K * R18 ** self.lambda_17 R13 = R45 - 2 * R17 d13C_VPDB = 1000 * (R13 / self.R13_VPDB - 1) return d13C_VPDB, d18O_VSMOW def D47fromTeq(self, fCo2eqD47 = 'petersen', priority = 'new'): ''' Find all samples for which `Teq` is specified, compute equilibrium Δ<sub>47</sub> value for that temperature, and add treat these samples as additional anchors. __Parameters__ + `fCo2eqD47`: Which CO<sub>2</sub> equilibrium law to use (`petersen`: [Petersen et al. (2019)]; `wang`: [Wang et al. (2019)]). + `priority`: if `replace`: forget old anchors and only use the new ones; if `new`: keep pre-existing anchors but update them in case of conflict between old and new Δ<sub>47</sub> values; if `old`: keep pre-existing anchors but preserve their original Δ<sub>47</sub> values in case of conflict. [Petersen et al. (2019)]: https://doi.org/10.1029/2018GC008127 [Wang et al. (2019)]: https://doi.org/10.1016/j.gca.2004.05.039 ''' f = { 'petersen': fCO2eqD47_Petersen, 'wang': fCO2eqD47_Wang, }[fCo2eqD47] foo = {} for r in self: if 'Teq' in r: if r['Sample'] in foo: assert foo[r['Sample']] == f(r['Teq']), f'Different values of `Teq` provided for sample `{r["Sample"]}`.' else: foo[r['Sample']] = f(r['Teq']) else: assert r['Sample'] not in foo, f'`Teq` is inconsistently specified for sample `{r["Sample"]}`.' if priority == 'replace': self.Nominal_D47 = {} for s in foo: if priority != 'old' or s not in self.Nominal_D47: self.Nominal_D47[s] = foo[s] @make_verbal def crunch(self, verbose = ''): ''' Compute bulk composition and raw clumped isotope anomalies for all analyses. ''' for r in self: self.compute_bulk_and_clumping_deltas(r) self.standardize_d13C() self.standardize_d18O() self.msg(f"Crunched {len(self)} analyses.") def fill_in_missing_info(self, session = 'mySession'): ''' Fill in optional fields with default values ''' for i,r in enumerate(self): if 'D17O' not in r: r['D17O'] = 0. if 'UID' not in r: r['UID'] = f'#{i+1}' if 'Session' not in r: r['Session'] = session for k in ['d48', 'd49']: if k not in r: r[k] = np.nan def standardize_d13C(self): ''' Perform δ<sup>13</sup>C standadization within each session `s` according to `self.sessions[s]['d13C_standardization_method']`, which is defined by default by `D47data.refresh_sessions()`as equal to `self.d13C_STANDARDIZATION_METHOD`, but may be redefined abitrarily at a later stage. ''' for s in self.sessions: if self.sessions[s]['d13C_standardization_method'] in ['1pt', '2pt']: XY = [(r['d13C_VPDB'], self.Nominal_d13C_VPDB[r['Sample']]) for r in self.sessions[s]['data'] if r['Sample'] in self.Nominal_d13C_VPDB] X,Y = zip(*XY) if self.sessions[s]['d13C_standardization_method'] == '1pt': offset = np.mean(Y) - np.mean(X) for r in self.sessions[s]['data']: r['d13C_VPDB'] += offset elif self.sessions[s]['d13C_standardization_method'] == '2pt': a,b = np.polyfit(X,Y,1) for r in self.sessions[s]['data']: r['d13C_VPDB'] = a * r['d13C_VPDB'] + b def standardize_d18O(self): ''' Perform δ<sup>18</sup>O standadization within each session `s` according to `self.ALPHA_18O_ACID_REACTION` and `self.sessions[s]['d18O_standardization_method']`, which is defined by default by `D47data.refresh_sessions()`as equal to `self.d18O_STANDARDIZATION_METHOD`, but may be redefined abitrarily at a later stage. ''' for s in self.sessions: if self.sessions[s]['d18O_standardization_method'] in ['1pt', '2pt']: XY = [(r['d18O_VSMOW'], self.Nominal_d18O_VPDB[r['Sample']]) for r in self.sessions[s]['data'] if r['Sample'] in self.Nominal_d18O_VPDB] X,Y = zip(*XY) Y = [(1000+y) * self.R18_VPDB * self.ALPHA_18O_ACID_REACTION / self.R18_VSMOW - 1000 for y in Y] if self.sessions[s]['d18O_standardization_method'] == '1pt': offset = np.mean(Y) - np.mean(X) for r in self.sessions[s]['data']: r['d18O_VSMOW'] += offset elif self.sessions[s]['d18O_standardization_method'] == '2pt': a,b = np.polyfit(X,Y,1) for r in self.sessions[s]['data']: r['d18O_VSMOW'] = a * r['d18O_VSMOW'] + b def compute_bulk_and_clumping_deltas(self, r): ''' Compute δ<sup>13</sup>C<sub>VPDB</sub>, δ<sup>18</sup>O<sub>VSMOW</sub>, and raw Δ<sub>47</sub>, Δ<sub>48</sub>, Δ<sub>49</sub> values for an analysis `r`. ''' # Compute working gas R13, R18, and isobar ratios R13_wg = self.R13_VPDB * (1 + r['d13Cwg_VPDB'] / 1000) R18_wg = self.R18_VSMOW * (1 + r['d18Owg_VSMOW'] / 1000) R45_wg, R46_wg, R47_wg, R48_wg, R49_wg = self.compute_isobar_ratios(R13_wg, R18_wg) # Compute analyte isobar ratios R45 = (1 + r['d45'] / 1000) * R45_wg R46 = (1 + r['d46'] / 1000) * R46_wg R47 = (1 + r['d47'] / 1000) * R47_wg R48 = (1 + r['d48'] / 1000) * R48_wg R49 = (1 + r['d49'] / 1000) * R49_wg r['d13C_VPDB'], r['d18O_VSMOW'] = self.compute_bulk_delta(R45, R46, D17O = r['D17O']) R13 = (1 + r['d13C_VPDB'] / 1000) * self.R13_VPDB R18 = (1 + r['d18O_VSMOW'] / 1000) * self.R18_VSMOW # Compute stochastic isobar ratios of the analyte R45stoch, R46stoch, R47stoch, R48stoch, R49stoch = self.compute_isobar_ratios( R13, R18, D17O = r['D17O'] ) # Check that R45/R45stoch and R46/R46stoch are undistinguishable from 1, # and raise a warning if the corresponding anomalies exceed 0.02 ppm. if (R45 / R45stoch - 1) > 5e-8: self.vmsg(f'This is unexpected: R45/R45stoch - 1 = {1e6 * (R45 / R45stoch - 1):.3f} ppm') if (R46 / R46stoch - 1) > 5e-8: self.vmsg(f'This is unexpected: R46/R46stoch - 1 = {1e6 * (R46 / R46stoch - 1):.3f} ppm') # Compute raw clumped isotope anomalies r['D47raw'] = 1000 * (R47 / R47stoch - 1) r['D48raw'] = 1000 * (R48 / R48stoch - 1) r['D49raw'] = 1000 * (R49 / R49stoch - 1) def compute_isobar_ratios(self, R13, R18, D17O=0, D47=0, D48=0, D49=0): ''' Compute isobar ratios for a sample with isotopic ratios `R13` and `R18`, optionally accounting for non-zero values of Δ<sup>17</sup>O (`D17O`) and clumped isotope anomalies (`D47`, `D48`, `D49`), all expressed in permil. ''' # Compute R17 R17 = self.R17_VSMOW * np.exp(D17O / 1000) * (R18 / self.R18_VSMOW) ** self.lambda_17 # Compute isotope concentrations C12 = (1 + R13) ** -1 C13 = C12 * R13 C16 = (1 + R17 + R18) ** -1 C17 = C16 * R17 C18 = C16 * R18 # Compute stochastic isotopologue concentrations C626 = C16 * C12 * C16 C627 = C16 * C12 * C17 * 2 C628 = C16 * C12 * C18 * 2 C636 = C16 * C13 * C16 C637 = C16 * C13 * C17 * 2 C638 = C16 * C13 * C18 * 2 C727 = C17 * C12 * C17 C728 = C17 * C12 * C18 * 2 C737 = C17 * C13 * C17 C738 = C17 * C13 * C18 * 2 C828 = C18 * C12 * C18 C838 = C18 * C13 * C18 # Compute stochastic isobar ratios R45 = (C636 + C627) / C626 R46 = (C628 + C637 + C727) / C626 R47 = (C638 + C728 + C737) / C626 R48 = (C738 + C828) / C626 R49 = C838 / C626 # Account for stochastic anomalies R47 *= 1 + D47 / 1000 R48 *= 1 + D48 / 1000 R49 *= 1 + D49 / 1000 # Return isobar ratios return R45, R46, R47, R48, R49 def split_samples(self, samples_to_split = 'all', grouping = 'by_uid'): ''' Split unknown samples by UID (treat all analyses as different samples) or by session (treat analyses of a given sample in different sessions as different samples). __Parameters__ + `samples_to_split`: a list of samples to split, e.g., `['IAEA-C1', 'IAEA-C2']` + `grouping`: `by_uid` | `by_session` ''' if samples_to_split == 'all': samples_to_split = [s for s in self.unknowns] gkeys = {'by_uid':'UID', 'by_session':'Session'} self.grouping = grouping.lower() if self.grouping in gkeys: gkey = gkeys[self.grouping] for r in self: if r['Sample'] in samples_to_split: r['Sample_original'] = r['Sample'] r['Sample'] = f"{r['Sample']}__{r[gkey]}" elif r['Sample'] in self.unknowns: r['Sample_original'] = r['Sample'] self.refresh_samples() def unsplit_samples(self, tables = True): ''' Reverse the effects of `D47data.split_samples`. ''' unknowns_old = sorted({s for s in self.unknowns}) CM_old = self.standardization.covar[:,:] VD_old = self.standardization.params.valuesdict().copy() vars_old = self.standardization.var_names unknowns_new = sorted({r['Sample_original'] for r in self if 'Sample_original' in r}) Ns = len(vars_old) - len(unknowns_old) vars_new = vars_old[:Ns] + [f'D47_{pf(u)}' for u in unknowns_new] VD_new = {k: VD_old[k] for k in vars_old[:Ns]} W = np.zeros((len(vars_new), len(vars_old))) W[:Ns,:Ns] = np.eye(Ns) for u in unknowns_new: splits = sorted({r['Sample'] for r in self if 'Sample_original' in r and r['Sample_original'] == u}) if self.grouping == 'by_session': weights = [self.samples[s]['SE_D47']**-2 for s in splits] elif self.grouping == 'by_uid': weights = [1 for s in splits] sw = sum(weights) weights = [w/sw for w in weights] W[vars_new.index(f'D47_{pf(u)}'),[vars_old.index(f'D47_{pf(s)}') for s in splits]] = weights[:] # print('\nUnsplitting weights matrix:') # print('\n'.join([' '.join([f'{x:.1f}' if x else ' - ' for x in l]) for l in W])) # print('---') CM_new = W @ CM_old @ W.T V = W @ np.array([[VD_old[k]] for k in vars_old]) VD_new = {k:v[0] for k,v in zip(vars_new, V)} self.standardization.covar = CM_new self.standardization.params.valuesdict = lambda : VD_new self.standardization.var_names = vars_new for r in self: if r['Sample'] in self.unknowns: r['Sample_split'] = r['Sample'] r['Sample'] = r['Sample_original'] self.refresh_samples() self.consolidate_samples() self.repeatabilies() if tables: self.table_of_analyses() self.table_of_samples() def assign_timestamps(self): ''' Assign a time field `t` of type `float` to each analysis. If `TimeTag` is one of the data fields, `t` is equal within a given session to `TimeTag` minus the mean value of `TimeTag` for that session. Otherwise, `TimeTag` is by default equal to the index of each analysis in the dataset and `t` is defined as above. ''' for session in self.sessions: sdata = self.sessions[session]['data'] try: t0 = np.mean([r['TimeTag'] for r in sdata]) for r in sdata: r['t'] = r['TimeTag'] - t0 # print('DEBUG - USING TimeTag <-----------------------------------') except KeyError: t0 = (len(sdata)-1)/2 for t,r in enumerate(sdata): r['t'] = t - t0 @make_verbal def standardize(self, method = 'pooled', weighted_sessions = [], consolidate = True, consolidate_tables = False, consolidate_plots = False, ): ''' Compute absolute Δ<sub>47</sub> values for all replicate analyses and for sample averages. If `method` argument is set to `'pooled'`, the standardization processes all sessions in a single step, assuming that all samples (anchors and unknowns alike) are homogeneous (i.e. that their true Δ<sub>47</sub> value does not change between sessions). If `method` argument is set to `'indep_sessions'`, the standardization processes each session independently, based only on anchors analyses. ''' self.standardization_method = method self.assign_timestamps() if method == 'pooled': if weighted_sessions: for session_group in weighted_sessions: X = D47data([r for r in self if r['Session'] in session_group]) result = X.standardize(method = 'pooled', weighted_sessions = [], consolidate = False) w = np.sqrt(result.redchi) self.msg(f'Session group {session_group} MRSWD = {w:.4f}') for r in X: r['wD47raw'] *= w else: self.msg('All D47raw weights set to 1 ‰') for r in self: r['wD47raw'] = 1. params = Parameters() for k,session in enumerate(self.sessions): self.msg(f"Session {session}: scrambling_drift is {self.sessions[session]['scrambling_drift']}.") self.msg(f"Session {session}: slope_drift is {self.sessions[session]['slope_drift']}.") self.msg(f"Session {session}: wg_drift is {self.sessions[session]['wg_drift']}.") s = pf(session) params.add(f'a_{s}', value = 0.9) params.add(f'b_{s}', value = 0.) params.add(f'c_{s}', value = -0.9) params.add(f'a2_{s}', value = 0., vary = self.sessions[session]['scrambling_drift']) params.add(f'b2_{s}', value = 0., vary = self.sessions[session]['slope_drift']) params.add(f'c2_{s}', value = 0., vary = self.sessions[session]['wg_drift']) for sample in self.unknowns: params.add(f'D47_{pf(sample)}', value=0.6) def residuals(p): R = [] for r in self: session = pf(r['Session']) sample = pf(r['Sample']) if r['Sample'] in self.Nominal_D47: R += [ ( r['D47raw'] - ( p[f'a_{session}'] * self.Nominal_D47[r['Sample']] + p[f'b_{session}'] * r['d47'] + p[f'c_{session}'] + r['t'] * ( p[f'a2_{session}'] * self.Nominal_D47[r['Sample']] + p[f'b2_{session}'] * r['d47'] + p[f'c2_{session}'] ) ) ) / r['wD47raw'] ] else: R += [ ( r['D47raw'] - ( p[f'a_{session}'] * p[f'D47_{sample}'] + p[f'b_{session}'] * r['d47'] + p[f'c_{session}'] + r['t'] * ( p[f'a2_{session}'] * p[f'D47_{sample}'] + p[f'b2_{session}'] * r['d47'] + p[f'c2_{session}'] ) ) ) / r['wD47raw'] ] return R M = Minimizer(residuals, params) result = M.leastsq() self.Nf = result.nfree self.t95 = tstudent.ppf(1 - 0.05/2, self.Nf) # if self.verbose: # report_fit(result) for r in self: s = pf(r["Session"]) a = result.params.valuesdict()[f'a_{s}'] b = result.params.valuesdict()[f'b_{s}'] c = result.params.valuesdict()[f'c_{s}'] a2 = result.params.valuesdict()[f'a2_{s}'] b2 = result.params.valuesdict()[f'b2_{s}'] c2 = result.params.valuesdict()[f'c2_{s}'] r['D47'] = (r['D47raw'] - c - b * r['d47'] - c2 * r['t'] - b2 * r['t'] * r['d47']) / (a + a2 * r['t']) self.standardization = result if consolidate: self.consolidate(tables = consolidate_tables, plots = consolidate_plots) return result elif method == 'indep_sessions': if weighted_sessions: for session_group in weighted_sessions: X = D47data([r for r in self if r['Session'] in session_group]) X.Nominal_D47 = self.Nominal_D47.copy() X.refresh() # This is only done to assign r['wD47raw'] for r in X: X.standardize(method = method, weighted_sessions = [], consolidate = False) self.msg(f'D47raw weights set to {1000*X[0]["wD47raw"]:.1f} ppm for sessions in {session_group}') else: self.msg('All weights set to 1 ‰') for r in self: r['wD47raw'] = 1 for session in self.sessions: s = self.sessions[session] p_names = ['a', 'b', 'c', 'a2', 'b2', 'c2'] p_active = [True, True, True, s['scrambling_drift'], s['slope_drift'], s['wg_drift']] s['Np'] = sum(p_active) sdata = s['data'] A = np.array([ [ self.Nominal_D47[r['Sample']] / r['wD47raw'], r['d47'] / r['wD47raw'], 1 / r['wD47raw'], self.Nominal_D47[r['Sample']] * r['t'] / r['wD47raw'], r['d47'] * r['t'] / r['wD47raw'], r['t'] / r['wD47raw'] ] for r in sdata if r['Sample'] in self.anchors ])[:,p_active] # only keep columns for the active parameters Y = np.array([[r['D47raw'] / r['wD47raw']] for r in sdata if r['Sample'] in self.anchors]) s['Na'] = Y.size CM = linalg.inv(A.T @ A) bf = (CM @ A.T @ Y).T[0,:] k = 0 for n,a in zip(p_names, p_active): if a: s[n] = bf[k] # self.msg(f'{n} = {bf[k]}') k += 1 else: s[n] = 0. # self.msg(f'{n} = 0.0') for r in sdata : a, b, c, a2, b2, c2 = s['a'], s['b'], s['c'], s['a2'], s['b2'], s['c2'] r['D47'] = (r['D47raw'] - c - b * r['d47'] - c2 * r['t'] - b2 * r['t'] * r['d47']) / (a + a2 * r['t']) r['wD47'] = r['wD47raw'] / (a + a2 * r['t']) s['CM'] = np.zeros((6,6)) i = 0 k_active = [j for j,a in enumerate(p_active) if a] for j,a in enumerate(p_active): if a: s['CM'][j,k_active] = CM[i,:] i += 1 if not weighted_sessions: w = self.rmswd()['rmswd'] for r in self: r['wD47'] *= w r['wD47raw'] *= w for session in self.sessions: self.sessions[session]['CM'] *= w**2 for session in self.sessions: s = self.sessions[session] s['SE_a'] = s['CM'][0,0]**.5 s['SE_b'] = s['CM'][1,1]**.5 s['SE_c'] = s['CM'][2,2]**.5 s['SE_a2'] = s['CM'][3,3]**.5 s['SE_b2'] = s['CM'][4,4]**.5 s['SE_c2'] = s['CM'][5,5]**.5 if not weighted_sessions: self.Nf = len(self) - len(self.unknowns) - np.sum([self.sessions[s]['Np'] for s in self.sessions]) else: self.Nf = 0 for sg in weighted_sessions: self.Nf += self.rmswd(sessions = sg)['Nf'] self.t95 = tstudent.ppf(1 - 0.05/2, self.Nf) avgD47 = { sample: np.mean([r['D47'] for r in self if r['Sample'] == sample]) for sample in self.samples } chi2 = np.sum([(r['D47'] - avgD47[r['Sample']])**2 for r in self]) rD47 = (chi2/self.Nf)**.5 self.repeatability['sigma_47'] = rD47 if consolidate: self.consolidate(tables = consolidate_tables, plots = consolidate_plots) def report(self): ''' Prints a report on the standardization fit. ''' report_fit(self.standardization) def standardization_error(self, session, d47, D47, t = 0): ''' Compute standardization error for a given session and (δ<sub>47</sub>, Δ<sub>47</sub>) composition. ''' a = self.sessions[session]['a'] b = self.sessions[session]['b'] c = self.sessions[session]['c'] a2 = self.sessions[session]['a2'] b2 = self.sessions[session]['b2'] c2 = self.sessions[session]['c2'] CM = self.sessions[session]['CM'] x, y = D47, d47 z = a * x + b * y + c + a2 * x * t + b2 * y * t + c2 * t # x = (z - b*y - b2*y*t - c - c2*t) / (a+a2*t) dxdy = -(b+b2*t) / (a+a2*t) dxdz = 1. / (a+a2*t) dxda = -x / (a+a2*t) dxdb = -y / (a+a2*t) dxdc = -1. / (a+a2*t) dxda2 = -x * a2 / (a+a2*t) dxdb2 = -y * t / (a+a2*t) dxdc2 = -t / (a+a2*t) V = np.array([dxda, dxdb, dxdc, dxda2, dxdb2, dxdc2]) sx = (V @ CM @ V.T) ** .5 return sx @make_verbal def summary(self, dir = 'results', filename = 'summary.csv', save_to_file = True, print_out = True): ''' Print out an/or save to disk a summary of the standardization results. __Parameters__ + `dir`: the directory in which to save the table + `filename`: the name to the csv file to write to + `save_to_file`: whether to save the table to disk + `print_out`: whether to print out the table ''' out = [] out += [['N samples (anchors + unknowns)', f"{len(self.samples)} ({len(self.anchors)} + {len(self.unknowns)})"]] out += [['N analyses (anchors + unknowns)', f"{len(self)} ({len([r for r in self if r['Sample'] in self.anchors])} + {len([r for r in self if r['Sample'] in self.unknowns])})"]] out += [['Repeatability of δ13C_VPDB', f"{1000 * self.repeatability['r_d13C_VPDB']:.1f} ppm"]] out += [['Repeatability of δ18O_VSMOW', f"{1000 * self.repeatability['r_d18O_VSMOW']:.1f} ppm"]] out += [['Repeatability of Δ47 (anchors)', f"{1000 * self.repeatability['r_D47a']:.1f} ppm"]] out += [['Repeatability of Δ47 (unknowns)', f"{1000 * self.repeatability['r_D47u']:.1f} ppm"]] out += [['Repeatability of Δ47 (all)', f"{1000 * self.repeatability['r_D47']:.1f} ppm"]] out += [['Model degrees of freedom', f"{self.Nf}"]] out += [['Student\'s 95% t-factor', f"{self.t95:.2f}"]] out += [['Standardization method', self.standardization_method]] if save_to_file: if not os.path.exists(dir): os.makedirs(dir) with open(f'{dir}/{filename}', 'w') as fid: fid.write(make_csv(out)) if print_out: self.msg('\n' + pretty_table(out, header = 0)) return out @make_verbal def table_of_sessions(self, dir = 'results', filename = 'sessions.csv', save_to_file = True, print_out = True): ''' Print out an/or save to disk a table of sessions. __Parameters__ + `dir`: the directory in which to save the table + `filename`: the name to the csv file to write to + `save_to_file`: whether to save the table to disk + `print_out`: whether to print out the table ''' include_a2 = any([self.sessions[session]['scrambling_drift'] for session in self.sessions]) include_b2 = any([self.sessions[session]['slope_drift'] for session in self.sessions]) include_c2 = any([self.sessions[session]['wg_drift'] for session in self.sessions]) out = [['Session','Na','Nu','d13Cwg_VPDB','d18Owg_VSMOW','r_d13C','r_d18O','r_D47','a ± SE','1e3 x b ± SE','c ± SE']] if include_a2: out[-1] += ['a2 ± SE'] if include_b2: out[-1] += ['b2 ± SE'] if include_c2: out[-1] += ['c2 ± SE'] for session in self.sessions: out += [[ session, f"{self.sessions[session]['Na']}", f"{self.sessions[session]['Nu']}", f"{self.sessions[session]['d13Cwg_VPDB']:.3f}", f"{self.sessions[session]['d18Owg_VSMOW']:.3f}", f"{self.sessions[session]['r_d13C_VPDB']:.4f}", f"{self.sessions[session]['r_d18O_VSMOW']:.4f}", f"{self.sessions[session]['r_D47']:.4f}", f"{self.sessions[session]['a']:.3f} ± {self.sessions[session]['SE_a']:.3f}", f"{1e3*self.sessions[session]['b']:.3f} ± {1e3*self.sessions[session]['SE_b']:.3f}", f"{self.sessions[session]['c']:.3f} ± {self.sessions[session]['SE_c']:.3f}", ]] if include_a2: if self.sessions[session]['scrambling_drift']: out[-1] += [f"{self.sessions[session]['a2']:.1e} ± {self.sessions[session]['SE_a2']:.1e}"] else: out[-1] += [''] if include_b2: if self.sessions[session]['slope_drift']: out[-1] += [f"{self.sessions[session]['b2']:.1e} ± {self.sessions[session]['SE_b2']:.1e}"] else: out[-1] += [''] if include_c2: if self.sessions[session]['wg_drift']: out[-1] += [f"{self.sessions[session]['c2']:.1e} ± {self.sessions[session]['SE_c2']:.1e}"] else: out[-1] += [''] if save_to_file: if not os.path.exists(dir): os.makedirs(dir) with open(f'{dir}/{filename}', 'w') as fid: fid.write(make_csv(out)) if print_out: self.msg('\n' + pretty_table(out)) return out @make_verbal def table_of_analyses(self, dir = 'results', filename = 'analyses.csv', save_to_file = True, print_out = True): ''' Print out an/or save to disk a table of analyses. __Parameters__ + `dir`: the directory in which to save the table + `filename`: the name to the csv file to write to + `save_to_file`: whether to save the table to disk + `print_out`: whether to print out the table ''' out = [['UID','Session','Sample']] extra_fields = [f for f in [('SampleMass','.2f'),('ColdFingerPressure','.1f'),('AcidReactionYield','.3f')] if f[0] in {k for r in self for k in r}] for f in extra_fields: out[-1] += [f[0]] out[-1] += ['d13Cwg_VPDB','d18Owg_VSMOW','d45','d46','d47','d48','d49','d13C_VPDB','d18O_VSMOW','D47raw','D48raw','D49raw','D47'] for r in self: out += [[f"{r['UID']}",f"{r['Session']}",f"{r['Sample']}"]] for f in extra_fields: out[-1] += [f"{r[f[0]]:{f[1]}}"] out[-1] += [ f"{r['d13Cwg_VPDB']:.3f}", f"{r['d18Owg_VSMOW']:.3f}", f"{r['d45']:.6f}", f"{r['d46']:.6f}", f"{r['d47']:.6f}", f"{r['d48']:.6f}", f"{r['d49']:.6f}", f"{r['d13C_VPDB']:.6f}", f"{r['d18O_VSMOW']:.6f}", f"{r['D47raw']:.6f}", f"{r['D48raw']:.6f}", f"{r['D49raw']:.6f}", f"{r['D47']:.6f}" ] if save_to_file: if not os.path.exists(dir): os.makedirs(dir) with open(f'{dir}/{filename}', 'w') as fid: fid.write(make_csv(out)) if print_out: self.msg('\n' + pretty_table(out)) return out @make_verbal def table_of_samples(self, dir = 'results', filename = 'samples.csv', save_to_file = True, print_out = True): ''' Print out an/or save to disk a table of samples. __Parameters__ + `dir`: the directory in which to save the table + `filename`: the name to the csv file to write to + `save_to_file`: whether to save the table to disk + `print_out`: whether to print out the table ''' out = [['Sample','N','d13C_VPDB','d18O_VSMOW','D47','SE','95% CL','SD','p_Levene']] for sample in self.anchors: out += [[ f"{sample}", f"{self.samples[sample]['N']}", f"{self.samples[sample]['d13C_VPDB']:.2f}", f"{self.samples[sample]['d18O_VSMOW']:.2f}", f"{self.samples[sample]['D47']:.4f}",'','', f"{self.samples[sample]['SD_D47']:.4f}" if self.samples[sample]['N'] > 1 else '', '' ]] for sample in self.unknowns: out += [[ f"{sample}", f"{self.samples[sample]['N']}", f"{self.samples[sample]['d13C_VPDB']:.2f}", f"{self.samples[sample]['d18O_VSMOW']:.2f}", f"{self.samples[sample]['D47']:.4f}", f"{self.samples[sample]['SE_D47']:.4f}", f"± {self.samples[sample]['SE_D47']*self.t95:.4f}", f"{self.samples[sample]['SD_D47']:.4f}" if self.samples[sample]['N'] > 1 else '', f"{self.samples[sample]['p_Levene']:.3f}" if self.samples[sample]['N'] > 2 else '' ]] if save_to_file: if not os.path.exists(dir): os.makedirs(dir) with open(f'{dir}/{filename}', 'w') as fid: fid.write(make_csv(out)) if print_out: self.msg('\n'+pretty_table(out)) return out def plot_sessions(self, dir = 'plots', figsize = (8,8)): ''' Generate session plots and save them to disk. __Parameters__ + `dir`: the directory in which to save the plots + `figsize`: the width and height (in inches) of each plot ''' if not os.path.exists(dir): os.makedirs(dir) for session in self.sessions: sp = self.plot_single_session(session, xylimits = 'constant') ppl.savefig(f'{dir}/D47model_{session}.pdf') ppl.close(sp.fig) # def plot_sessions_old(self, dir = 'plots', figsize = (8,8)): # ''' # Generate session plots and save them to disk. # # __Parameters__ # # + `dir`: the directory in which to save the plots # + `figsize`: the width and height (in inches) of each plot # ''' # if not os.path.exists(dir): # os.makedirs(dir) # anchor_color = 'r' # unknown_color = 'b' # # xmin = min([r['d47'] for r in self]) # xmax = max([r['d47'] for r in self]) # xmin -= (xmax - xmin)/10 # xmax += (xmax - xmin)/11 # # ymin = min([r['D47'] for r in self]) # ymax = max([r['D47'] for r in self]) # ymin -= (ymax - ymin)/10 # ymax += (ymax - ymin)/11 # # repl_kw = dict(ls = 'None', marker = 'x', mfc = 'None', ms = 4, mew = .67, alpha = 1) # avg_kw = dict(ls = '-', marker = 'None', lw = .67, alpha = .67) # for session in self.sessions: # fig = ppl.figure( figsize = figsize) # for sample in self.anchors: # db = [r for r in self.samples[sample]['data'] if r['Session'] == session] # if len(db): # repl_kw['mec'] = anchor_color # X = [r['d47'] for r in db] # Y = [r['D47'] for r in db] # ppl.plot(X, Y, **repl_kw) # # avg_kw['color'] = anchor_color # X = [min(X)-.5, max(X)+.5] # Y = [self.samples[sample]['D47']] * 2 # ppl.plot(X, Y, **avg_kw) # # outliers = [r for r in db if abs(r['D47'] - self.Nominal_D47[r['Sample']])>.1] # for r in outliers: # print(r['UID'], r['Sample'], r['D47']) # X = [r['d47'] for r in outliers] # Y = [r['D47'] for r in outliers] # ppl.plot(X, Y, 'o', mfc = 'None', mec = (1,0,1), mew = 2) # # for sample in self.unknowns: # # db = [r for r in self.samples[sample]['data'] if r['Session'] == session] # if len(db): # repl_kw['mec'] = unknown_color # X = [r['d47'] for r in db] # Y = [r['D47'] for r in db] # ppl.plot(X, Y, **repl_kw) # # avg_kw['color'] = unknown_color # X = [min(X)-.19, max(X)+.19] # Y = [self.samples[sample]['D47']] * 2 # ppl.plot(X, Y, **avg_kw) # # XI,YI = np.meshgrid(np.linspace(xmin, xmax), np.linspace(ymin, ymax)) # SI = np.array([[self.standardization_error(session, xi, yi) for xi in XI[0,:]] for yi in YI[:,0]]) # rng = np.max(SI) - np.min(SI) # if rng <= 0.01: # cinterval = 0.001 # elif rng <= 0.03: # cinterval = 0.004 # elif rng <= 0.1: # cinterval = 0.01 # elif rng <= 0.3: # cinterval = 0.03 # else: # cinterval = 0.1 # cval = [np.ceil(SI.min() / .001) * .001 + k * cinterval for k in range(int(np.ceil((SI.max() - SI.min()) / cinterval)))] # cs = ppl.contour(XI, YI, SI, cval, colors = anchor_color, alpha = .5) # ppl.clabel(cs) # # ppl.axis([xmin, xmax, ymin, ymax]) # ppl.xlabel('δ$_{47}$ (‰ WG)') # ppl.ylabel('Δ$_{47}$ (‰)') # ppl.grid(alpha = .15) # ppl.title(session, weight = 'bold') # ppl.savefig(f'{dir}/D47model_{session}.pdf') # ppl.close(fig) # def sample_D47_covar(self, sample_1, sample_2 = ''): # ''' # Covariance between Δ47 values of samples # # Returns the covariance (or the variance, if sample_1 == sample_2) # between the average Δ47 values of two samples. Also returns the # variance if only sample_1 is specified. # ''' # i = self.standardization.var_names.index(f'D47_{pf(sample_1)}') # if sample_2 in [sample_1,'']: # return self.standardization.covar[i,i] # else: # j = self.standardization.var_names.index(f'D47_{pf(sample_2)}') # return self.standardization.covar[i,j] # @make_verbal def consolidate_samples(self): ''' Compile various statistics for each sample. For each anchor sample: + `D47`: the nominal Δ<sub>47</sub> value for this anchor, specified by `self.Nominal_D47` + `SE_D47`: set to zero by definition For each unknown sample: + `D47`: the standardized Δ<sub>47</sub> value for this unknown + `SE_D47`: the standard error of Δ<sub>47</sub> for this unknown For each anchor and unknown: + `N`: the total number of analyses of this sample + `SD_D47`: the “sample” (in the statistical sense) standard deviation for this sample + `d13C_VPDB`: the average δ<sup>13</sup>C<sub>VPDB</sub> value for this sample + `d18O_VSMOW`: the average δ<sup>18</sup>O<sub>VSMOW</sub> value for this sample (as CO<sub>2</sub>) + `p_Levene`: the p-value from a [Levene test] of equal variance, indicating whether the Δ<sub>47</sub> repeatability this sample differs significantly from that observed for the reference sample specified by `self.LEVENE_REF_SAMPLE`. [Levene test]: https://en.wikipedia.org/wiki/Levene%27s_test ''' D47_ref_pop = [r['D47'] for r in self.samples[self.LEVENE_REF_SAMPLE]['data']] for sample in self.samples: self.samples[sample]['N'] = len(self.samples[sample]['data']) if self.samples[sample]['N'] > 1: self.samples[sample]['SD_D47'] = stdev([r['D47'] for r in self.samples[sample]['data']]) self.samples[sample]['d13C_VPDB'] = np.mean([r['d13C_VPDB'] for r in self.samples[sample]['data']]) self.samples[sample]['d18O_VSMOW'] = np.mean([r['d18O_VSMOW'] for r in self.samples[sample]['data']]) D47_pop = [r['D47'] for r in self.samples[sample]['data']] if len(D47_pop) > 2: self.samples[sample]['p_Levene'] = levene(D47_ref_pop, D47_pop, center = 'median')[1] if self.standardization_method == 'pooled': for sample in self.anchors: self.samples[sample]['D47'] = self.Nominal_D47[sample] self.samples[sample]['SE_D47'] = 0. for sample in self.unknowns: self.samples[sample]['D47'] = self.standardization.params.valuesdict()[f'D47_{pf(sample)}'] self.samples[sample]['SE_D47'] = self.sample_D47_covar(sample)**.5 elif self.standardization_method == 'indep_sessions': for sample in self.anchors: self.samples[sample]['D47'] = self.Nominal_D47[sample] self.samples[sample]['SE_D47'] = 0. for sample in self.unknowns: self.msg(f'Consolidating sample {sample}') self.unknowns[sample]['session_D47'] = {} session_avg = [] for session in self.sessions: sdata = [r for r in self.sessions[session]['data'] if r['Sample'] == sample] if sdata: self.msg(f'{sample} found in session {session}') avg_D47 = np.mean([r['D47'] for r in sdata]) avg_d47 = np.mean([r['d47'] for r in sdata]) # !! TODO: sigma_s below does not account for temporal changes in standardization error sigma_s = self.standardization_error(session, avg_d47, avg_D47) sigma_u = sdata[0]['wD47raw'] / self.sessions[session]['a'] / len(sdata)**.5 session_avg.append([avg_D47, (sigma_u**2 + sigma_s**2)**.5]) self.unknowns[sample]['session_D47'][session] = session_avg[-1] self.samples[sample]['D47'], self.samples[sample]['SE_D47'] = w_avg(*zip(*session_avg)) weights = {s: self.unknowns[sample]['session_D47'][s][1]**-2 for s in self.unknowns[sample]['session_D47']} wsum = sum([weights[s] for s in weights]) for s in weights: self.unknowns[sample]['session_D47'][s] += [self.unknowns[sample]['session_D47'][s][1]**-2 / wsum] def consolidate_sessions(self): ''' Compile various statistics for each session. + `Na`: Number of anchor analyses in the session + `Nu`: Number of unknown analyses in the session + `r_d13C_VPDB`: δ<sup>13</sup>C<sub>VPDB</sub> repeatability of analyses within the session + `r_d18O_VSMOW`: δ<sup>18</sup>O<sub>VSMOW</sub> repeatability of analyses within the session + `r_D47`: Δ<sub>47</sub> repeatability of analyses within the session + `a`: scrambling factor + `b`: compositional slope + `c`: WG offset + `SE_a`: Model stadard erorr of `a` + `SE_b`: Model stadard erorr of `b` + `SE_c`: Model stadard erorr of `c` + `scrambling_drift` (boolean): whether to allow a temporal drift in the scrambling factor (`a`) + `slope_drift` (boolean): whether to allow a temporal drift in the compositional slope (`b`) + `wg_drift` (boolean): whether to allow a temporal drift in the WG offset (`c`) + `a2`: scrambling factor drift + `b2`: compositional slope drift + `c2`: WG offset drift + `Np`: Number of standardization parameters to fit + `CM`: model covariance matrix for (`a`, `b`, `c`, `a2`, `b2`, `c2`) + `d13Cwg_VPDB`: δ<sup>13</sup>C<sub>VPDB</sub> of WG + `d18Owg_VSMOW`: δ<sup>18</sup>O<sub>VSMOW</sub> of WG ''' for session in self.sessions: if 'd13Cwg_VPDB' not in self.sessions[session]: self.sessions[session]['d13Cwg_VPDB'] = self.sessions[session]['data'][0]['d13Cwg_VPDB'] if 'd18Owg_VSMOW' not in self.sessions[session]: self.sessions[session]['d18Owg_VSMOW'] = self.sessions[session]['data'][0]['d18Owg_VSMOW'] self.sessions[session]['Na'] = len([r for r in self.sessions[session]['data'] if r['Sample'] in self.anchors]) self.sessions[session]['Nu'] = len([r for r in self.sessions[session]['data'] if r['Sample'] in self.unknowns]) self.msg(f'Computing repeatabilities for session {session}') self.sessions[session]['r_d13C_VPDB'] = self.compute_r('d13C_VPDB', samples = 'anchors', sessions = [session]) self.sessions[session]['r_d18O_VSMOW'] = self.compute_r('d18O_VSMOW', samples = 'anchors', sessions = [session]) self.sessions[session]['r_D47'] = self.compute_r('D47', sessions = [session]) if self.standardization_method == 'pooled': for session in self.sessions: self.sessions[session]['Np'] = 3 for k in ['scrambling', 'slope', 'wg']: if self.sessions[session][f'{k}_drift']: self.sessions[session]['Np'] += 1 self.sessions[session]['a'] = self.standardization.params.valuesdict()[f'a_{pf(session)}'] i = self.standardization.var_names.index(f'a_{pf(session)}') self.sessions[session]['SE_a'] = self.standardization.covar[i,i]**.5 self.sessions[session]['b'] = self.standardization.params.valuesdict()[f'b_{pf(session)}'] i = self.standardization.var_names.index(f'b_{pf(session)}') self.sessions[session]['SE_b'] = self.standardization.covar[i,i]**.5 self.sessions[session]['c'] = self.standardization.params.valuesdict()[f'c_{pf(session)}'] i = self.standardization.var_names.index(f'c_{pf(session)}') self.sessions[session]['SE_c'] = self.standardization.covar[i,i]**.5 self.sessions[session]['a2'] = self.standardization.params.valuesdict()[f'a2_{pf(session)}'] if self.sessions[session]['scrambling_drift']: i = self.standardization.var_names.index(f'a2_{pf(session)}') self.sessions[session]['SE_a2'] = self.standardization.covar[i,i]**.5 else: self.sessions[session]['SE_a2'] = 0. self.sessions[session]['b2'] = self.standardization.params.valuesdict()[f'b2_{pf(session)}'] if self.sessions[session]['slope_drift']: i = self.standardization.var_names.index(f'b2_{pf(session)}') self.sessions[session]['SE_b2'] = self.standardization.covar[i,i]**.5 else: self.sessions[session]['SE_b2'] = 0. self.sessions[session]['c2'] = self.standardization.params.valuesdict()[f'c2_{pf(session)}'] if self.sessions[session]['wg_drift']: i = self.standardization.var_names.index(f'c2_{pf(session)}') self.sessions[session]['SE_c2'] = self.standardization.covar[i,i]**.5 else: self.sessions[session]['SE_c2'] = 0. i = self.standardization.var_names.index(f'a_{pf(session)}') j = self.standardization.var_names.index(f'b_{pf(session)}') k = self.standardization.var_names.index(f'c_{pf(session)}') CM = np.zeros((6,6)) CM[:3,:3] = self.standardization.covar[[i,j,k],:][:,[i,j,k]] try: i2 = self.standardization.var_names.index(f'a2_{pf(session)}') CM[3,[0,1,2,3]] = self.standardization.covar[i2,[i,j,k,i2]] CM[[0,1,2,3],3] = self.standardization.covar[[i,j,k,i2],i2] try: j2 = self.standardization.var_names.index(f'b2_{pf(session)}') CM[3,4] = self.standardization.covar[i2,j2] CM[4,3] = self.standardization.covar[j2,i2] except ValueError: pass try: k2 = self.standardization.var_names.index(f'c2_{pf(session)}') CM[3,5] = self.standardization.covar[i2,k2] CM[5,3] = self.standardization.covar[k2,i2] except ValueError: pass except ValueError: pass try: j2 = self.standardization.var_names.index(f'b2_{pf(session)}') CM[4,[0,1,2,4]] = self.standardization.covar[j2,[i,j,k,j2]] CM[[0,1,2,4],4] = self.standardization.covar[[i,j,k,j2],j2] try: k2 = self.standardization.var_names.index(f'c2_{pf(session)}') CM[4,5] = self.standardization.covar[j2,k2] CM[5,4] = self.standardization.covar[k2,j2] except ValueError: pass except ValueError: pass try: k2 = self.standardization.var_names.index(f'c2_{pf(session)}') CM[5,[0,1,2,5]] = self.standardization.covar[k2,[i,j,k,k2]] CM[[0,1,2,5],5] = self.standardization.covar[[i,j,k,k2],k2] except ValueError: pass self.sessions[session]['CM'] = CM elif self.standardization_method == 'indep_sessions': pass @make_verbal def repeatabilies(self): ''' Compute analytical repeatabilities for δ<sup>13</sup>C<sub>VPDB</sub>, δ<sup>18</sup>O<sub>VSMOW</sub>, Δ<sub>47</sub> (for all samples, for anchors, and for unknowns). ''' self.msg('Computing reproducibilities for all sessions') self.repeatability['r_d13C_VPDB'] = self.compute_r('d13C_VPDB', samples = 'anchors') self.repeatability['r_d18O_VSMOW'] = self.compute_r('d18O_VSMOW', samples = 'anchors') N_anchor_analyses = len([r for r in self if r['Sample'] in self.anchors]) self.repeatability['r_D47a'] = self.compute_r('D47', samples = 'anchors') self.repeatability['r_D47a'] /= ( (N_anchor_analyses - np.sum([self.sessions[s]['Np'] for s in self.sessions])) / (N_anchor_analyses - len(self.anchors)) )**.5 self.repeatability['r_D47u'] = self.compute_r('D47', samples = 'unknowns') self.repeatability['r_D47'] = self.compute_r('D47', samples = 'all samples') self.repeatability['r_D47'] /= ( (len(self) - len(self.unknowns) - np.sum([self.sessions[s]['Np'] for s in self.sessions])) / (len(self) - len(self.samples)) )**.5 @make_verbal def consolidate(self, tables = True, plots = True): ''' Collect information about samples, sessions and repeatabilities. ''' self.consolidate_samples() self.consolidate_sessions() self.repeatabilies() if tables: self.summary() self.table_of_sessions() self.table_of_analyses() self.table_of_samples() if plots: self.plot_sessions() @make_verbal def rmswd(self, samples = 'all samples', sessions = 'all sessions', ): ''' Compute the root mean squared weighted deviation, χ2 and corresponding degrees of freedom of `[r['D47'] for r in self]` ''' if samples == 'all samples': mysamples = [k for k in self.samples] elif samples == 'anchors': mysamples = [k for k in self.anchors] elif samples == 'unknowns': mysamples = [k for k in self.unknowns] else: mysamples = samples if sessions == 'all sessions': sessions = [k for k in self.sessions] chisq, Nf = 0, 0 for sample in mysamples : G = [ r for r in self if r['Sample'] == sample and r['Session'] in sessions ] if len(G) > 1 : X, sX = w_avg([r['D47'] for r in G], [r['wD47'] for r in G]) Nf += (len(G) - 1) chisq += np.sum([ ((r['D47']-X)/r['wD47'])**2 for r in G]) r = (chisq / Nf)**.5 if Nf > 0 else 0 self.msg(f'RMSWD of r["D47"] is {r:.6f} for {samples}.') return {'rmswd': r, 'chisq': chisq, 'Nf': Nf} @make_verbal def compute_r(self, key, samples = 'all samples', sessions = 'all sessions'): ''' Compute the repeatability of `[r[key] for r in self]` ''' # NB: it's debatable whether rD47 should be computed # with Nf = len(self)-len(self.samples) instead of # Nf = len(self) - len(self.unknwons) - 3*len(self.sessions) if samples == 'all samples': mysamples = [k for k in self.samples] elif samples == 'anchors': mysamples = [k for k in self.anchors] elif samples == 'unknowns': mysamples = [k for k in self.unknowns] else: mysamples = samples if sessions == 'all sessions': sessions = [k for k in self.sessions] chisq, Nf = 0, 0 for sample in mysamples : X = [ r[key] for r in self if r['Sample'] == sample and r['Session'] in sessions ] if len(X) > 1 : Nf += len(X) - 1 chisq += np.sum([ (x-np.mean(X))**2 for x in X ]) r = (chisq / Nf)**.5 if Nf > 0 else 0 self.msg(f'Repeatability of r["{key}"] is {1000*r:.1f} ppm for {samples}.') return r def sample_average(self, samples, weights = 'equal', normalize = True): ''' Weighted average Δ<sub>47</sub> value of a group of samples, accounting for covariance. Returns the weighed average Δ47 value and associated SE of a group of samples. Weights are equal by default. If `normalize` is true, `weights` will be rescaled so that their sum equals 1. __Examples__ ```python self.sample_average(['X','Y'], [1, 2]) ``` returns the value and SE of [Δ<sub>47</sub>(X) + 2 Δ<sub>47</sub>(Y)]/3, where Δ<sub>47</sub>(X) and Δ<sub>47</sub>(Y) are the average Δ<sub>47</sub> values of samples X and Y, respectively. ```python self.sample_average(['X','Y'], [1, -1], normalize = False) ``` returns the value and SE of the difference Δ<sub>47</sub>(X) - Δ<sub>47</sub>(Y). ''' if weights == 'equal': weights = [1/len(samples)] * len(samples) if normalize: s = sum(weights) weights = [w/s for w in weights] try: # indices = [self.standardization.var_names.index(f'D47_{pf(sample)}') for sample in samples] # C = self.standardization.covar[indices,:][:,indices] C = np.array([[self.sample_D47_covar(x, y) for x in samples] for y in samples]) X = [self.samples[sample]['D47'] for sample in samples] return correlated_sum(X, C, weights) except ValueError: return (0., 0.) def sample_D47_covar(self, sample1, sample2 = ''): ''' Covariance between Δ<sub>47</sub> values of samples Returns the error covariance between the average Δ<sub>47</sub> values of two samples. If if only `sample_1` is specified, or if `sample_1 == sample_2`), returns the Δ<sub>47</sub> variance for that sample. ''' if sample2 == '': sample2 = sample1 if self.standardization_method == 'pooled': i = self.standardization.var_names.index(f'D47_{pf(sample1)}') j = self.standardization.var_names.index(f'D47_{pf(sample2)}') return self.standardization.covar[i, j] elif self.standardization_method == 'indep_sessions': if sample1 == sample2: return self.samples[sample1]['SE_D47']**2 else: c = 0 for session in self.sessions: sdata1 = [r for r in self.sessions[session]['data'] if r['Sample'] == sample1] sdata2 = [r for r in self.sessions[session]['data'] if r['Sample'] == sample2] if sdata1 and sdata2: a = self.sessions[session]['a'] # !! TODO: CM below does not account for temporal changes in standardization parameters CM = self.sessions[session]['CM'][:3,:3] avg_D47_1 = np.mean([r['D47'] for r in sdata1]) avg_d47_1 = np.mean([r['d47'] for r in sdata1]) avg_D47_2 = np.mean([r['D47'] for r in sdata2]) avg_d47_2 = np.mean([r['d47'] for r in sdata2]) c += ( self.unknowns[sample1]['session_D47'][session][2] * self.unknowns[sample2]['session_D47'][session][2] * np.array([[avg_D47_1, avg_d47_1, 1]]) @ CM @ np.array([[avg_D47_2, avg_d47_2, 1]]).T ) / a**2 return float(c) def sample_D47_correl(self, sample1, sample2 = ''): ''' Correlation between Δ<sub>47</sub> errors of samples Returns the error correlation between the average Δ47 values of two samples. ''' if sample2 == '' or sample2 == sample1: return 1. return ( self.sample_D47_covar(sample1, sample2) / self.unknowns[sample1]['SE_D47'] / self.unknowns[sample2]['SE_D47'] ) def plot_single_session(self, session, kw_plot_anchors = dict(ls='None', marker='x', mec=(.75, 0, 0), mew = .75, ms = 4), kw_plot_unknowns = dict(ls='None', marker='x', mec=(0, 0, .75), mew = .75, ms = 4), kw_plot_anchor_avg = dict(ls='-', marker='None', color=(.75, 0, 0), lw = .75), kw_plot_unknown_avg = dict(ls='-', marker='None', color=(0, 0, .75), lw = .75), kw_contour_error = dict(colors = [[0, 0, 0]], alpha = .5, linewidths = 0.75), xylimits = 'free', # | 'constant' x_label = 'δ$_{47}$ (‰)', y_label = 'Δ$_{47}$ (‰)', error_contour_interval = 'auto', fig = 'new', ): ''' Generate plot for a single session ''' out = SessionPlot() if fig == 'new': out.fig = ppl.figure(figsize = (6,6)) ppl.subplots_adjust(.1,.1,.9,.9) out.anchor_analyses, = ppl.plot( [r['d47'] for r in self.sessions[session]['data'] if r['Sample'] in self.anchors], [r['D47'] for r in self.sessions[session]['data'] if r['Sample'] in self.anchors], **kw_plot_anchors) out.unknown_analyses, = ppl.plot( [r['d47'] for r in self.sessions[session]['data'] if r['Sample'] in self.unknowns], [r['D47'] for r in self.sessions[session]['data'] if r['Sample'] in self.unknowns], **kw_plot_unknowns) out.anchor_avg = ppl.plot( np.array([ np.array([-.5, .5]) + np.mean([r['d47'] for r in self.sessions[session]['data'] if r['Sample'] == sample]) for sample in self.anchors]).T, np.array([ np.array([0, 0]) + self.Nominal_D47[sample] for sample in self.anchors]).T, '-', **kw_plot_anchor_avg) out.unknown_avg = ppl.plot( np.array([ np.array([-.5, .5]) + np.mean([r['d47'] for r in self.sessions[session]['data'] if r['Sample'] == sample]) for sample in self.unknowns]).T, np.array([ np.array([0, 0]) + self.unknowns[sample]['D47'] for sample in self.unknowns]).T, '-', **kw_plot_unknown_avg) if xylimits == 'constant': x = [r['d47'] for r in self] y = [r['D47'] for r in self] x1, x2, y1, y2 = np.min(x), np.max(x), np.min(y), np.max(y) w, h = x2-x1, y2-y1 x1 -= w/20 x2 += w/20 y1 -= h/20 y2 += h/20 ppl.axis([x1, x2, y1, y2]) elif xylimits != 'free': x1, x2, y1, y2 = ppl.axis() else: x1, x2, y1, y2 = ppl.axis(xylimits) if error_contour_interval != 'none': xi, yi = np.linspace(x1, x2), np.linspace(y1, y2) XI,YI = np.meshgrid(xi, yi) SI = np.array([[self.standardization_error(session, x, y) for x in xi] for y in yi]) if error_contour_interval == 'auto': rng = np.max(SI) - np.min(SI) if rng <= 0.01: cinterval = 0.001 elif rng <= 0.03: cinterval = 0.004 elif rng <= 0.1: cinterval = 0.01 elif rng <= 0.3: cinterval = 0.03 elif rng <= 1.: cinterval = 0.1 else: cinterval = 0.5 else: cinterval = error_contour_interval cval = np.arange(np.ceil(SI.min() / .001) * .001, np.ceil(SI.max() / .001 + 1) * .001, cinterval) out.contour = ppl.contour(XI, YI, SI, cval, **kw_contour_error) out.clabel = ppl.clabel(out.contour) ppl.xlabel(x_label) ppl.ylabel(y_label) ppl.title(session, weight = 'bold') ppl.grid(alpha = .2) out.ax = ppl.gca() return outAncestors
- builtins.list
Class variables
var ALPHA_18O_ACID_REACTION-
Specifies the 18O/16O fractionation factor generally applicable to acid reactions in the dataset. Currently used by
D47data.wg(),D47data.standardize_d13C(), andD47data.standardize_d18O().By default equal to 1.008129 (calcite reacted at 90 °C, Kim et al., 2007).
var LEVENE_REF_SAMPLE-
After the Δ47 standardization step, each sample is tested to assess whether the Δ47 variance within all analyses for that sample differs significantly from that observed for a given reference sample (using Levene's test, which yields a p-value corresponding to the null hypothesis that the underlying variances are equal).
LEVENE_REF_SAMPLE(by default equal to'ETH-3') specifies which sample should be used as a reference for this test. var Nominal_D47-
Nominal Δ47 values assigned to the anchor samples, used by
D47data.standardize()to standardize unknown samples to an absolute Δ47 reference frame.By default equal to
{'ETH-1': 0.258, 'ETH-2': 0.256, 'ETH-3': 0.691}after Bernasconi et al. (2018). var Nominal_d13C_VPDB-
Nominal δ13CVPDB values assigned to carbonate standards, used by
D47data.standardize_d13C().By default equal to
{'ETH-1': 2.02, 'ETH-2': -10.17, 'ETH-3': 1.71}after Bernasconi et al. (2018). var Nominal_d18O_VPDB-
Nominal δ18OVPDB values assigned to carbonate standards, used by
D47data.standardize_d18O().By default equal to
{'ETH-1': -2.19, 'ETH-2': -18.69, 'ETH-3': -1.78}after Bernasconi et al. (2018). var R13_VPDB-
Absolute (13C/12C) ratio of VPDB. By default equal to 0.01118 (Chang & Li, 1990)
var R17_VPDB-
Absolute (17O/16C) ratio of VPDB. By definition equal to
R17_VSMOW * 1.03092 ** lambda_17. var R17_VSMOW-
Absolute (17O/16C) ratio of VSMOW. By default equal to 0.00038475 (Assonov & Brenninkmeijer, 2003, rescaled to
R13_VPDB) var R18_VPDB-
Absolute (18O/16C) ratio of VPDB. By definition equal to
R18_VSMOW * 1.03092. var R18_VSMOW-
Absolute (18O/16C) ratio of VSMOW. By default equal to 0.0020052 (Baertschi, 1976)
var SAMPLE_CONSTRAINING_WG_COMPOSITION-
Specifies the name, δ13CVPDB and δ18OVPDB of the carbonate standard used by
D47data.wg()to compute the isotopic composition of the working gas in each session.By default equal to
('ETH-3', 1.71, -1.78)after Bernasconi et al. (2018). var d13C_STANDARDIZATION_METHOD-
Method by which to standardize δ13C values:
none: do not apply any δ13C standardization.'1pt': within each session, offset all initial δ13C values so as to minimize the difference between final δ13CVPDB values andNominal_d13C_VPDB(averaged over all analyses for whichNominal_d13C_VPDBis defined).'2pt': within each session, apply a affine trasformation to all δ13C values so as to minimize the difference between final δ13CVPDB values andNominal_d13C_VPDB(averaged over all analyses for whichNominal_d13C_VPDBis defined).
var d18O_STANDARDIZATION_METHOD-
Method by which to standardize δ18O values:
none: do not apply any δ18O standardization.'1pt': within each session, offset all initial δ18O values so as to minimize the difference between final δ18OVPDB values andNominal_d18O_VPDB(averaged over all analyses for whichNominal_d18O_VPDBis defined).'2pt': within each session, apply a affine trasformation to all δ18O values so as to minimize the difference between final δ18OVPDB values andNominal_d18O_VPDB(averaged over all analyses for whichNominal_d18O_VPDBis defined).
var lambda_17-
Mass-dependent exponent for triple oxygen isotopes. By default equal to 0.528 (Barkan & Luz, 2005)
Methods
def D47fromTeq(self, fCo2eqD47='petersen', priority='new')-
Find all samples for which
Teqis specified, compute equilibrium Δ47 value for that temperature, and add treat these samples as additional anchors.Parameters
fCo2eqD47: Which CO2 equilibrium law to use (petersen: Petersen et al. (2019);wang: Wang et al. (2019)).priority: ifreplace: forget old anchors and only use the new ones; ifnew: keep pre-existing anchors but update them in case of conflict between old and new Δ47 values; ifold: keep pre-existing anchors but preserve their original Δ47 values in case of conflict.
Expand source code
def D47fromTeq(self, fCo2eqD47 = 'petersen', priority = 'new'): ''' Find all samples for which `Teq` is specified, compute equilibrium Δ<sub>47</sub> value for that temperature, and add treat these samples as additional anchors. __Parameters__ + `fCo2eqD47`: Which CO<sub>2</sub> equilibrium law to use (`petersen`: [Petersen et al. (2019)]; `wang`: [Wang et al. (2019)]). + `priority`: if `replace`: forget old anchors and only use the new ones; if `new`: keep pre-existing anchors but update them in case of conflict between old and new Δ<sub>47</sub> values; if `old`: keep pre-existing anchors but preserve their original Δ<sub>47</sub> values in case of conflict. [Petersen et al. (2019)]: https://doi.org/10.1029/2018GC008127 [Wang et al. (2019)]: https://doi.org/10.1016/j.gca.2004.05.039 ''' f = { 'petersen': fCO2eqD47_Petersen, 'wang': fCO2eqD47_Wang, }[fCo2eqD47] foo = {} for r in self: if 'Teq' in r: if r['Sample'] in foo: assert foo[r['Sample']] == f(r['Teq']), f'Different values of `Teq` provided for sample `{r["Sample"]}`.' else: foo[r['Sample']] = f(r['Teq']) else: assert r['Sample'] not in foo, f'`Teq` is inconsistently specified for sample `{r["Sample"]}`.' if priority == 'replace': self.Nominal_D47 = {} for s in foo: if priority != 'old' or s not in self.Nominal_D47: self.Nominal_D47[s] = foo[s] def assign_timestamps(self)-
Assign a time field
tof typefloatto each analysis.If
TimeTagis one of the data fields,tis equal within a given session toTimeTagminus the mean value ofTimeTagfor that session. Otherwise,TimeTagis by default equal to the index of each analysis in the dataset andtis defined as above.Expand source code
def assign_timestamps(self): ''' Assign a time field `t` of type `float` to each analysis. If `TimeTag` is one of the data fields, `t` is equal within a given session to `TimeTag` minus the mean value of `TimeTag` for that session. Otherwise, `TimeTag` is by default equal to the index of each analysis in the dataset and `t` is defined as above. ''' for session in self.sessions: sdata = self.sessions[session]['data'] try: t0 = np.mean([r['TimeTag'] for r in sdata]) for r in sdata: r['t'] = r['TimeTag'] - t0 # print('DEBUG - USING TimeTag <-----------------------------------') except KeyError: t0 = (len(sdata)-1)/2 for t,r in enumerate(sdata): r['t'] = t - t0 def compute_bulk_and_clumping_deltas(self, r)-
Compute δ13CVPDB, δ18OVSMOW, and raw Δ47, Δ48, Δ49 values for an analysis
r.Expand source code
def compute_bulk_and_clumping_deltas(self, r): ''' Compute δ<sup>13</sup>C<sub>VPDB</sub>, δ<sup>18</sup>O<sub>VSMOW</sub>, and raw Δ<sub>47</sub>, Δ<sub>48</sub>, Δ<sub>49</sub> values for an analysis `r`. ''' # Compute working gas R13, R18, and isobar ratios R13_wg = self.R13_VPDB * (1 + r['d13Cwg_VPDB'] / 1000) R18_wg = self.R18_VSMOW * (1 + r['d18Owg_VSMOW'] / 1000) R45_wg, R46_wg, R47_wg, R48_wg, R49_wg = self.compute_isobar_ratios(R13_wg, R18_wg) # Compute analyte isobar ratios R45 = (1 + r['d45'] / 1000) * R45_wg R46 = (1 + r['d46'] / 1000) * R46_wg R47 = (1 + r['d47'] / 1000) * R47_wg R48 = (1 + r['d48'] / 1000) * R48_wg R49 = (1 + r['d49'] / 1000) * R49_wg r['d13C_VPDB'], r['d18O_VSMOW'] = self.compute_bulk_delta(R45, R46, D17O = r['D17O']) R13 = (1 + r['d13C_VPDB'] / 1000) * self.R13_VPDB R18 = (1 + r['d18O_VSMOW'] / 1000) * self.R18_VSMOW # Compute stochastic isobar ratios of the analyte R45stoch, R46stoch, R47stoch, R48stoch, R49stoch = self.compute_isobar_ratios( R13, R18, D17O = r['D17O'] ) # Check that R45/R45stoch and R46/R46stoch are undistinguishable from 1, # and raise a warning if the corresponding anomalies exceed 0.02 ppm. if (R45 / R45stoch - 1) > 5e-8: self.vmsg(f'This is unexpected: R45/R45stoch - 1 = {1e6 * (R45 / R45stoch - 1):.3f} ppm') if (R46 / R46stoch - 1) > 5e-8: self.vmsg(f'This is unexpected: R46/R46stoch - 1 = {1e6 * (R46 / R46stoch - 1):.3f} ppm') # Compute raw clumped isotope anomalies r['D47raw'] = 1000 * (R47 / R47stoch - 1) r['D48raw'] = 1000 * (R48 / R48stoch - 1) r['D49raw'] = 1000 * (R49 / R49stoch - 1) def compute_bulk_delta(self, R45, R46, D17O=0)-
Compute δ13CVPDB and δ18OVSMOW, by solving the generalized form of equation (17) from Brand et al. (2010), assuming that δ18OVSMOW is not too big (0 ± 50 ‰) and solving the corresponding second-order Taylor polynomial. (Appendix A of Daëron et al., 2016)
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def compute_bulk_delta(self, R45, R46, D17O = 0): ''' Compute δ<sup>13</sup>C<sub>VPDB</sub> and δ<sup>18</sup>O<sub>VSMOW</sub>, by solving the generalized form of equation (17) from [Brand et al. (2010)], assuming that δ<sup>18</sup>O<sub>VSMOW</sub> is not too big (0 ± 50 ‰) and solving the corresponding second-order Taylor polynomial. (Appendix A of [Daëron et al., 2016]) [Brand et al. (2010)]: https://doi.org/10.1351/PAC-REP-09-01-05 [Daëron et al., 2016]: https://doi.org/10.1016/j.chemgeo.2016.08.014 ''' K = np.exp(D17O / 1000) * self.R17_VSMOW * self.R18_VSMOW ** -self.lambda_17 A = -3 * K ** 2 * self.R18_VSMOW ** (2 * self.lambda_17) B = 2 * K * R45 * self.R18_VSMOW ** self.lambda_17 C = 2 * self.R18_VSMOW D = -R46 aa = A * self.lambda_17 * (2 * self.lambda_17 - 1) + B * self.lambda_17 * (self.lambda_17 - 1) / 2 bb = 2 * A * self.lambda_17 + B * self.lambda_17 + C cc = A + B + C + D d18O_VSMOW = 1000 * (-bb + (bb ** 2 - 4 * aa * cc) ** .5) / (2 * aa) R18 = (1 + d18O_VSMOW / 1000) * self.R18_VSMOW R17 = K * R18 ** self.lambda_17 R13 = R45 - 2 * R17 d13C_VPDB = 1000 * (R13 / self.R13_VPDB - 1) return d13C_VPDB, d18O_VSMOW def compute_isobar_ratios(self, R13, R18, D17O=0, D47=0, D48=0, D49=0)-
Compute isobar ratios for a sample with isotopic ratios
R13andR18, optionally accounting for non-zero values of Δ17O (D17O) and clumped isotope anomalies (D47,D48,D49), all expressed in permil.Expand source code
def compute_isobar_ratios(self, R13, R18, D17O=0, D47=0, D48=0, D49=0): ''' Compute isobar ratios for a sample with isotopic ratios `R13` and `R18`, optionally accounting for non-zero values of Δ<sup>17</sup>O (`D17O`) and clumped isotope anomalies (`D47`, `D48`, `D49`), all expressed in permil. ''' # Compute R17 R17 = self.R17_VSMOW * np.exp(D17O / 1000) * (R18 / self.R18_VSMOW) ** self.lambda_17 # Compute isotope concentrations C12 = (1 + R13) ** -1 C13 = C12 * R13 C16 = (1 + R17 + R18) ** -1 C17 = C16 * R17 C18 = C16 * R18 # Compute stochastic isotopologue concentrations C626 = C16 * C12 * C16 C627 = C16 * C12 * C17 * 2 C628 = C16 * C12 * C18 * 2 C636 = C16 * C13 * C16 C637 = C16 * C13 * C17 * 2 C638 = C16 * C13 * C18 * 2 C727 = C17 * C12 * C17 C728 = C17 * C12 * C18 * 2 C737 = C17 * C13 * C17 C738 = C17 * C13 * C18 * 2 C828 = C18 * C12 * C18 C838 = C18 * C13 * C18 # Compute stochastic isobar ratios R45 = (C636 + C627) / C626 R46 = (C628 + C637 + C727) / C626 R47 = (C638 + C728 + C737) / C626 R48 = (C738 + C828) / C626 R49 = C838 / C626 # Account for stochastic anomalies R47 *= 1 + D47 / 1000 R48 *= 1 + D48 / 1000 R49 *= 1 + D49 / 1000 # Return isobar ratios return R45, R46, R47, R48, R49 def compute_r(self, key, samples='all samples', sessions='all sessions')-
Compute the repeatability of
[r[key] for r in self]Expand source code
@make_verbal def compute_r(self, key, samples = 'all samples', sessions = 'all sessions'): ''' Compute the repeatability of `[r[key] for r in self]` ''' # NB: it's debatable whether rD47 should be computed # with Nf = len(self)-len(self.samples) instead of # Nf = len(self) - len(self.unknwons) - 3*len(self.sessions) if samples == 'all samples': mysamples = [k for k in self.samples] elif samples == 'anchors': mysamples = [k for k in self.anchors] elif samples == 'unknowns': mysamples = [k for k in self.unknowns] else: mysamples = samples if sessions == 'all sessions': sessions = [k for k in self.sessions] chisq, Nf = 0, 0 for sample in mysamples : X = [ r[key] for r in self if r['Sample'] == sample and r['Session'] in sessions ] if len(X) > 1 : Nf += len(X) - 1 chisq += np.sum([ (x-np.mean(X))**2 for x in X ]) r = (chisq / Nf)**.5 if Nf > 0 else 0 self.msg(f'Repeatability of r["{key}"] is {1000*r:.1f} ppm for {samples}.') return r def consolidate(self, tables=True, plots=True)-
Collect information about samples, sessions and repeatabilities.
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@make_verbal def consolidate(self, tables = True, plots = True): ''' Collect information about samples, sessions and repeatabilities. ''' self.consolidate_samples() self.consolidate_sessions() self.repeatabilies() if tables: self.summary() self.table_of_sessions() self.table_of_analyses() self.table_of_samples() if plots: self.plot_sessions() def consolidate_samples(self)-
Compile various statistics for each sample.
For each anchor sample:
D47: the nominal Δ47 value for this anchor, specified byself.Nominal_D47SE_D47: set to zero by definition
For each unknown sample:
D47: the standardized Δ47 value for this unknownSE_D47: the standard error of Δ47 for this unknown
For each anchor and unknown:
N: the total number of analyses of this sampleSD_D47: the “sample” (in the statistical sense) standard deviation for this sampled13C_VPDB: the average δ13CVPDB value for this sampled18O_VSMOW: the average δ18OVSMOW value for this sample (as CO2)p_Levene: the p-value from a Levene test of equal variance, indicating whether the Δ47 repeatability this sample differs significantly from that observed for the reference sample specified byself.LEVENE_REF_SAMPLE.
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@make_verbal def consolidate_samples(self): ''' Compile various statistics for each sample. For each anchor sample: + `D47`: the nominal Δ<sub>47</sub> value for this anchor, specified by `self.Nominal_D47` + `SE_D47`: set to zero by definition For each unknown sample: + `D47`: the standardized Δ<sub>47</sub> value for this unknown + `SE_D47`: the standard error of Δ<sub>47</sub> for this unknown For each anchor and unknown: + `N`: the total number of analyses of this sample + `SD_D47`: the “sample” (in the statistical sense) standard deviation for this sample + `d13C_VPDB`: the average δ<sup>13</sup>C<sub>VPDB</sub> value for this sample + `d18O_VSMOW`: the average δ<sup>18</sup>O<sub>VSMOW</sub> value for this sample (as CO<sub>2</sub>) + `p_Levene`: the p-value from a [Levene test] of equal variance, indicating whether the Δ<sub>47</sub> repeatability this sample differs significantly from that observed for the reference sample specified by `self.LEVENE_REF_SAMPLE`. [Levene test]: https://en.wikipedia.org/wiki/Levene%27s_test ''' D47_ref_pop = [r['D47'] for r in self.samples[self.LEVENE_REF_SAMPLE]['data']] for sample in self.samples: self.samples[sample]['N'] = len(self.samples[sample]['data']) if self.samples[sample]['N'] > 1: self.samples[sample]['SD_D47'] = stdev([r['D47'] for r in self.samples[sample]['data']]) self.samples[sample]['d13C_VPDB'] = np.mean([r['d13C_VPDB'] for r in self.samples[sample]['data']]) self.samples[sample]['d18O_VSMOW'] = np.mean([r['d18O_VSMOW'] for r in self.samples[sample]['data']]) D47_pop = [r['D47'] for r in self.samples[sample]['data']] if len(D47_pop) > 2: self.samples[sample]['p_Levene'] = levene(D47_ref_pop, D47_pop, center = 'median')[1] if self.standardization_method == 'pooled': for sample in self.anchors: self.samples[sample]['D47'] = self.Nominal_D47[sample] self.samples[sample]['SE_D47'] = 0. for sample in self.unknowns: self.samples[sample]['D47'] = self.standardization.params.valuesdict()[f'D47_{pf(sample)}'] self.samples[sample]['SE_D47'] = self.sample_D47_covar(sample)**.5 elif self.standardization_method == 'indep_sessions': for sample in self.anchors: self.samples[sample]['D47'] = self.Nominal_D47[sample] self.samples[sample]['SE_D47'] = 0. for sample in self.unknowns: self.msg(f'Consolidating sample {sample}') self.unknowns[sample]['session_D47'] = {} session_avg = [] for session in self.sessions: sdata = [r for r in self.sessions[session]['data'] if r['Sample'] == sample] if sdata: self.msg(f'{sample} found in session {session}') avg_D47 = np.mean([r['D47'] for r in sdata]) avg_d47 = np.mean([r['d47'] for r in sdata]) # !! TODO: sigma_s below does not account for temporal changes in standardization error sigma_s = self.standardization_error(session, avg_d47, avg_D47) sigma_u = sdata[0]['wD47raw'] / self.sessions[session]['a'] / len(sdata)**.5 session_avg.append([avg_D47, (sigma_u**2 + sigma_s**2)**.5]) self.unknowns[sample]['session_D47'][session] = session_avg[-1] self.samples[sample]['D47'], self.samples[sample]['SE_D47'] = w_avg(*zip(*session_avg)) weights = {s: self.unknowns[sample]['session_D47'][s][1]**-2 for s in self.unknowns[sample]['session_D47']} wsum = sum([weights[s] for s in weights]) for s in weights: self.unknowns[sample]['session_D47'][s] += [self.unknowns[sample]['session_D47'][s][1]**-2 / wsum] def consolidate_sessions(self)-
Compile various statistics for each session.
Na: Number of anchor analyses in the sessionNu: Number of unknown analyses in the sessionr_d13C_VPDB: δ13CVPDB repeatability of analyses within the sessionr_d18O_VSMOW: δ18OVSMOW repeatability of analyses within the sessionr_D47: Δ47 repeatability of analyses within the sessiona: scrambling factorb: compositional slopec: WG offsetSE_a: Model stadard erorr ofaSE_b: Model stadard erorr ofbSE_c: Model stadard erorr ofcscrambling_drift(boolean): whether to allow a temporal drift in the scrambling factor (a)slope_drift(boolean): whether to allow a temporal drift in the compositional slope (b)wg_drift(boolean): whether to allow a temporal drift in the WG offset (c)a2: scrambling factor driftb2: compositional slope driftc2: WG offset driftNp: Number of standardization parameters to fitCM: model covariance matrix for (a,b,c,a2,b2,c2)d13Cwg_VPDB: δ13CVPDB of WGd18Owg_VSMOW: δ18OVSMOW of WG
Expand source code
def consolidate_sessions(self): ''' Compile various statistics for each session. + `Na`: Number of anchor analyses in the session + `Nu`: Number of unknown analyses in the session + `r_d13C_VPDB`: δ<sup>13</sup>C<sub>VPDB</sub> repeatability of analyses within the session + `r_d18O_VSMOW`: δ<sup>18</sup>O<sub>VSMOW</sub> repeatability of analyses within the session + `r_D47`: Δ<sub>47</sub> repeatability of analyses within the session + `a`: scrambling factor + `b`: compositional slope + `c`: WG offset + `SE_a`: Model stadard erorr of `a` + `SE_b`: Model stadard erorr of `b` + `SE_c`: Model stadard erorr of `c` + `scrambling_drift` (boolean): whether to allow a temporal drift in the scrambling factor (`a`) + `slope_drift` (boolean): whether to allow a temporal drift in the compositional slope (`b`) + `wg_drift` (boolean): whether to allow a temporal drift in the WG offset (`c`) + `a2`: scrambling factor drift + `b2`: compositional slope drift + `c2`: WG offset drift + `Np`: Number of standardization parameters to fit + `CM`: model covariance matrix for (`a`, `b`, `c`, `a2`, `b2`, `c2`) + `d13Cwg_VPDB`: δ<sup>13</sup>C<sub>VPDB</sub> of WG + `d18Owg_VSMOW`: δ<sup>18</sup>O<sub>VSMOW</sub> of WG ''' for session in self.sessions: if 'd13Cwg_VPDB' not in self.sessions[session]: self.sessions[session]['d13Cwg_VPDB'] = self.sessions[session]['data'][0]['d13Cwg_VPDB'] if 'd18Owg_VSMOW' not in self.sessions[session]: self.sessions[session]['d18Owg_VSMOW'] = self.sessions[session]['data'][0]['d18Owg_VSMOW'] self.sessions[session]['Na'] = len([r for r in self.sessions[session]['data'] if r['Sample'] in self.anchors]) self.sessions[session]['Nu'] = len([r for r in self.sessions[session]['data'] if r['Sample'] in self.unknowns]) self.msg(f'Computing repeatabilities for session {session}') self.sessions[session]['r_d13C_VPDB'] = self.compute_r('d13C_VPDB', samples = 'anchors', sessions = [session]) self.sessions[session]['r_d18O_VSMOW'] = self.compute_r('d18O_VSMOW', samples = 'anchors', sessions = [session]) self.sessions[session]['r_D47'] = self.compute_r('D47', sessions = [session]) if self.standardization_method == 'pooled': for session in self.sessions: self.sessions[session]['Np'] = 3 for k in ['scrambling', 'slope', 'wg']: if self.sessions[session][f'{k}_drift']: self.sessions[session]['Np'] += 1 self.sessions[session]['a'] = self.standardization.params.valuesdict()[f'a_{pf(session)}'] i = self.standardization.var_names.index(f'a_{pf(session)}') self.sessions[session]['SE_a'] = self.standardization.covar[i,i]**.5 self.sessions[session]['b'] = self.standardization.params.valuesdict()[f'b_{pf(session)}'] i = self.standardization.var_names.index(f'b_{pf(session)}') self.sessions[session]['SE_b'] = self.standardization.covar[i,i]**.5 self.sessions[session]['c'] = self.standardization.params.valuesdict()[f'c_{pf(session)}'] i = self.standardization.var_names.index(f'c_{pf(session)}') self.sessions[session]['SE_c'] = self.standardization.covar[i,i]**.5 self.sessions[session]['a2'] = self.standardization.params.valuesdict()[f'a2_{pf(session)}'] if self.sessions[session]['scrambling_drift']: i = self.standardization.var_names.index(f'a2_{pf(session)}') self.sessions[session]['SE_a2'] = self.standardization.covar[i,i]**.5 else: self.sessions[session]['SE_a2'] = 0. self.sessions[session]['b2'] = self.standardization.params.valuesdict()[f'b2_{pf(session)}'] if self.sessions[session]['slope_drift']: i = self.standardization.var_names.index(f'b2_{pf(session)}') self.sessions[session]['SE_b2'] = self.standardization.covar[i,i]**.5 else: self.sessions[session]['SE_b2'] = 0. self.sessions[session]['c2'] = self.standardization.params.valuesdict()[f'c2_{pf(session)}'] if self.sessions[session]['wg_drift']: i = self.standardization.var_names.index(f'c2_{pf(session)}') self.sessions[session]['SE_c2'] = self.standardization.covar[i,i]**.5 else: self.sessions[session]['SE_c2'] = 0. i = self.standardization.var_names.index(f'a_{pf(session)}') j = self.standardization.var_names.index(f'b_{pf(session)}') k = self.standardization.var_names.index(f'c_{pf(session)}') CM = np.zeros((6,6)) CM[:3,:3] = self.standardization.covar[[i,j,k],:][:,[i,j,k]] try: i2 = self.standardization.var_names.index(f'a2_{pf(session)}') CM[3,[0,1,2,3]] = self.standardization.covar[i2,[i,j,k,i2]] CM[[0,1,2,3],3] = self.standardization.covar[[i,j,k,i2],i2] try: j2 = self.standardization.var_names.index(f'b2_{pf(session)}') CM[3,4] = self.standardization.covar[i2,j2] CM[4,3] = self.standardization.covar[j2,i2] except ValueError: pass try: k2 = self.standardization.var_names.index(f'c2_{pf(session)}') CM[3,5] = self.standardization.covar[i2,k2] CM[5,3] = self.standardization.covar[k2,i2] except ValueError: pass except ValueError: pass try: j2 = self.standardization.var_names.index(f'b2_{pf(session)}') CM[4,[0,1,2,4]] = self.standardization.covar[j2,[i,j,k,j2]] CM[[0,1,2,4],4] = self.standardization.covar[[i,j,k,j2],j2] try: k2 = self.standardization.var_names.index(f'c2_{pf(session)}') CM[4,5] = self.standardization.covar[j2,k2] CM[5,4] = self.standardization.covar[k2,j2] except ValueError: pass except ValueError: pass try: k2 = self.standardization.var_names.index(f'c2_{pf(session)}') CM[5,[0,1,2,5]] = self.standardization.covar[k2,[i,j,k,k2]] CM[[0,1,2,5],5] = self.standardization.covar[[i,j,k,k2],k2] except ValueError: pass self.sessions[session]['CM'] = CM elif self.standardization_method == 'indep_sessions': pass def crunch(self, verbose='')-
Compute bulk composition and raw clumped isotope anomalies for all analyses.
Expand source code
@make_verbal def crunch(self, verbose = ''): ''' Compute bulk composition and raw clumped isotope anomalies for all analyses. ''' for r in self: self.compute_bulk_and_clumping_deltas(r) self.standardize_d13C() self.standardize_d18O() self.msg(f"Crunched {len(self)} analyses.") def fill_in_missing_info(self, session='mySession')-
Fill in optional fields with default values
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def fill_in_missing_info(self, session = 'mySession'): ''' Fill in optional fields with default values ''' for i,r in enumerate(self): if 'D17O' not in r: r['D17O'] = 0. if 'UID' not in r: r['UID'] = f'#{i+1}' if 'Session' not in r: r['Session'] = session for k in ['d48', 'd49']: if k not in r: r[k] = np.nan def input(self, txt, sep='', session='')-
Read
txtstring in csv format to load analysis data into aD47dataobject.In the csv string, spaces befor and after field separators (
','by default) are optional. Each line corresponds to a single analysis.The required fields are:
UID: a unique identifierSession: an identifier for the analytical sessionSample: a sample identifierd45,d46,d47: the working-gas delta values
Independently known oxygen-17 anomalies may be provided as
D17O(in ‰ relative to VSMOW, λ =self.lambda_17), and are otherwise assumed to be zero. Working-gas deltasd48andd49may also be provided, and are also set to 0 otherwise.Parameters
txt: the csv string to readsep: csv separator delimiting the fields. By default, use,,;, ortxt.session: setSessionfield to this string for all analyses
Expand source code
def input(self, txt, sep = '', session = ''): ''' Read `txt` string in csv format to load analysis data into a `D47data` object. In the csv string, spaces befor and after field separators (`','` by default) are optional. Each line corresponds to a single analysis. The required fields are: + `UID`: a unique identifier + `Session`: an identifier for the analytical session + `Sample`: a sample identifier + `d45`, `d46`, `d47`: the working-gas delta values Independently known oxygen-17 anomalies may be provided as `D17O` (in ‰ relative to VSMOW, λ = `self.lambda_17`), and are otherwise assumed to be zero. Working-gas deltas `d48` and `d49` may also be provided, and are also set to 0 otherwise. __Parameters__ + `txt`: the csv string to read + `sep`: csv separator delimiting the fields. By default, use `,`, `;`, or `\t`, whichever appers most often in `txt`. + `session`: set `Session` field to this string for all analyses ''' if sep == '': sep = sorted(',;\t', key = lambda x: - txt.count(x))[0] txt = [[x.strip() for x in l.split(sep)] for l in txt.splitlines() if l.strip()] data = [{k: v if k in ['UID', 'Session', 'Sample'] else smart_type(v) for k,v in zip(txt[0], l)} for l in txt[1:]] if session != '': for r in data: r['Session'] = session self += data self.refresh() def log(self, *txts)-
Log a message to
self.logfileExpand source code
def log(self, *txts): ''' Log a message to `self.logfile` ''' if self.logfile: with open(self.logfile, 'a') as fid: for txt in txts: fid.write(f'\n{dt.now().strftime("%Y-%m-%d %H:%M:%S")} {f"[{self.prefix}]":<16} {txt}') def make_verbal(oldfun)-
Decorator to temporarily change
self.prefixand allow locally overridingself.verboseExpand source code
def make_verbal(oldfun): ''' Decorator to temporarily change `self.prefix` and allow locally overriding `self.verbose` ''' @wraps(oldfun) def newfun(*args, verbose = '', **kwargs): myself = args[0] oldprefix = myself.prefix myself.prefix = oldfun.__name__ if verbose != '': oldverbose = myself.verbose myself.verbose = verbose out = oldfun(*args, **kwargs) myself.prefix = oldprefix if verbose != '': myself.verbose = oldverbose return out return newfun def msg(self, txt)-
Log a message to
self.logfile, and print it out ifverbose = TrueExpand source code
def msg(self, txt): ''' Log a message to `self.logfile`, and print it out if `verbose = True` ''' self.log(txt) if self.verbose: print(f'{f"[{self.prefix}]":<16} {txt}') def plot_sessions(self, dir='plots', figsize=(8, 8))-
Generate session plots and save them to disk.
Parameters
dir: the directory in which to save the plotsfigsize: the width and height (in inches) of each plot
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def plot_sessions(self, dir = 'plots', figsize = (8,8)): ''' Generate session plots and save them to disk. __Parameters__ + `dir`: the directory in which to save the plots + `figsize`: the width and height (in inches) of each plot ''' if not os.path.exists(dir): os.makedirs(dir) for session in self.sessions: sp = self.plot_single_session(session, xylimits = 'constant') ppl.savefig(f'{dir}/D47model_{session}.pdf') ppl.close(sp.fig) def plot_single_session(self, session, kw_plot_anchors={'ls': 'None', 'marker': 'x', 'mec': (0.75, 0, 0), 'mew': 0.75, 'ms': 4}, kw_plot_unknowns={'ls': 'None', 'marker': 'x', 'mec': (0, 0, 0.75), 'mew': 0.75, 'ms': 4}, kw_plot_anchor_avg={'ls': '-', 'marker': 'None', 'color': (0.75, 0, 0), 'lw': 0.75}, kw_plot_unknown_avg={'ls': '-', 'marker': 'None', 'color': (0, 0, 0.75), 'lw': 0.75}, kw_contour_error={'colors': [[0, 0, 0]], 'alpha': 0.5, 'linewidths': 0.75}, xylimits='free', x_label='δ$_{47}$ (‰)', y_label='Δ$_{47}$ (‰)', error_contour_interval='auto', fig='new')-
Generate plot for a single session
Expand source code
def plot_single_session(self, session, kw_plot_anchors = dict(ls='None', marker='x', mec=(.75, 0, 0), mew = .75, ms = 4), kw_plot_unknowns = dict(ls='None', marker='x', mec=(0, 0, .75), mew = .75, ms = 4), kw_plot_anchor_avg = dict(ls='-', marker='None', color=(.75, 0, 0), lw = .75), kw_plot_unknown_avg = dict(ls='-', marker='None', color=(0, 0, .75), lw = .75), kw_contour_error = dict(colors = [[0, 0, 0]], alpha = .5, linewidths = 0.75), xylimits = 'free', # | 'constant' x_label = 'δ$_{47}$ (‰)', y_label = 'Δ$_{47}$ (‰)', error_contour_interval = 'auto', fig = 'new', ): ''' Generate plot for a single session ''' out = SessionPlot() if fig == 'new': out.fig = ppl.figure(figsize = (6,6)) ppl.subplots_adjust(.1,.1,.9,.9) out.anchor_analyses, = ppl.plot( [r['d47'] for r in self.sessions[session]['data'] if r['Sample'] in self.anchors], [r['D47'] for r in self.sessions[session]['data'] if r['Sample'] in self.anchors], **kw_plot_anchors) out.unknown_analyses, = ppl.plot( [r['d47'] for r in self.sessions[session]['data'] if r['Sample'] in self.unknowns], [r['D47'] for r in self.sessions[session]['data'] if r['Sample'] in self.unknowns], **kw_plot_unknowns) out.anchor_avg = ppl.plot( np.array([ np.array([-.5, .5]) + np.mean([r['d47'] for r in self.sessions[session]['data'] if r['Sample'] == sample]) for sample in self.anchors]).T, np.array([ np.array([0, 0]) + self.Nominal_D47[sample] for sample in self.anchors]).T, '-', **kw_plot_anchor_avg) out.unknown_avg = ppl.plot( np.array([ np.array([-.5, .5]) + np.mean([r['d47'] for r in self.sessions[session]['data'] if r['Sample'] == sample]) for sample in self.unknowns]).T, np.array([ np.array([0, 0]) + self.unknowns[sample]['D47'] for sample in self.unknowns]).T, '-', **kw_plot_unknown_avg) if xylimits == 'constant': x = [r['d47'] for r in self] y = [r['D47'] for r in self] x1, x2, y1, y2 = np.min(x), np.max(x), np.min(y), np.max(y) w, h = x2-x1, y2-y1 x1 -= w/20 x2 += w/20 y1 -= h/20 y2 += h/20 ppl.axis([x1, x2, y1, y2]) elif xylimits != 'free': x1, x2, y1, y2 = ppl.axis() else: x1, x2, y1, y2 = ppl.axis(xylimits) if error_contour_interval != 'none': xi, yi = np.linspace(x1, x2), np.linspace(y1, y2) XI,YI = np.meshgrid(xi, yi) SI = np.array([[self.standardization_error(session, x, y) for x in xi] for y in yi]) if error_contour_interval == 'auto': rng = np.max(SI) - np.min(SI) if rng <= 0.01: cinterval = 0.001 elif rng <= 0.03: cinterval = 0.004 elif rng <= 0.1: cinterval = 0.01 elif rng <= 0.3: cinterval = 0.03 elif rng <= 1.: cinterval = 0.1 else: cinterval = 0.5 else: cinterval = error_contour_interval cval = np.arange(np.ceil(SI.min() / .001) * .001, np.ceil(SI.max() / .001 + 1) * .001, cinterval) out.contour = ppl.contour(XI, YI, SI, cval, **kw_contour_error) out.clabel = ppl.clabel(out.contour) ppl.xlabel(x_label) ppl.ylabel(y_label) ppl.title(session, weight = 'bold') ppl.grid(alpha = .2) out.ax = ppl.gca() return out def read(self, filename, sep='', session='')-
Read file in csv format to load data into a
D47dataobject.In the csv file, spaces befor and after field separators (
','by default) are optional. Each line corresponds to a single analysis.The required fields are:
UID: a unique identifierSession: an identifier for the analytical sessionSample: a sample identifierd45,d46,d47: the working-gas delta values
Independently known oxygen-17 anomalies may be provided as
D17O(in ‰ relative to VSMOW, λ =self.lambda_17), and are otherwise assumed to be zero. Working-gas deltasd48andd49may also be provided, and are also set to 0 otherwise.Parameters
fileneme: the path of the file to readsep: csv separator delimiting the fieldssession: setSessionfield to this string for all analyses
Expand source code
def read(self, filename, sep = '', session = ''): ''' Read file in csv format to load data into a `D47data` object. In the csv file, spaces befor and after field separators (`','` by default) are optional. Each line corresponds to a single analysis. The required fields are: + `UID`: a unique identifier + `Session`: an identifier for the analytical session + `Sample`: a sample identifier + `d45`, `d46`, `d47`: the working-gas delta values Independently known oxygen-17 anomalies may be provided as `D17O` (in ‰ relative to VSMOW, λ = `self.lambda_17`), and are otherwise assumed to be zero. Working-gas deltas `d48` and `d49` may also be provided, and are also set to 0 otherwise. __Parameters__ + `fileneme`: the path of the file to read + `sep`: csv separator delimiting the fields + `session`: set `Session` field to this string for all analyses ''' with open(filename) as fid: self.input(fid.read(), sep = sep, session = session) def refresh(self, session='mySession')-
Update
self.sessions,self.samples,self.anchors, andself.unknowns.Expand source code
def refresh(self, session = 'mySession'): ''' Update `self.sessions`, `self.samples`, `self.anchors`, and `self.unknowns`. ''' self.fill_in_missing_info(session = session) self.refresh_sessions() self.refresh_samples() def refresh_samples(self)-
Define
self.samples,self.anchors, andself.unknowns.Expand source code
def refresh_samples(self): ''' Define `self.samples`, `self.anchors`, and `self.unknowns`. ''' self.samples = { s: {'data': [r for r in self if r['Sample'] == s]} for s in sorted({r['Sample'] for r in self}) } self.anchors = {s: self.samples[s] for s in self.samples if s in self.Nominal_D47} self.unknowns = {s: self.samples[s] for s in self.samples if s not in self.Nominal_D47} def refresh_sessions(self)-
Update
self.sessionsand setscrambling_drift,slope_drift, andwg_drifttoFalsefor all sessions.Expand source code
def refresh_sessions(self): ''' Update `self.sessions` and set `scrambling_drift`, `slope_drift`, and `wg_drift` to `False` for all sessions. ''' self.sessions = { s: {'data': [r for r in self if r['Session'] == s]} for s in sorted({r['Session'] for r in self}) } for s in self.sessions: self.sessions[s]['scrambling_drift'] = False self.sessions[s]['slope_drift'] = False self.sessions[s]['wg_drift'] = False self.sessions[s]['d13C_standardization_method'] = self.d13C_STANDARDIZATION_METHOD self.sessions[s]['d18O_standardization_method'] = self.d18O_STANDARDIZATION_METHOD def repeatabilies(self)-
Compute analytical repeatabilities for δ13CVPDB, δ18OVSMOW, Δ47 (for all samples, for anchors, and for unknowns).
Expand source code
@make_verbal def repeatabilies(self): ''' Compute analytical repeatabilities for δ<sup>13</sup>C<sub>VPDB</sub>, δ<sup>18</sup>O<sub>VSMOW</sub>, Δ<sub>47</sub> (for all samples, for anchors, and for unknowns). ''' self.msg('Computing reproducibilities for all sessions') self.repeatability['r_d13C_VPDB'] = self.compute_r('d13C_VPDB', samples = 'anchors') self.repeatability['r_d18O_VSMOW'] = self.compute_r('d18O_VSMOW', samples = 'anchors') N_anchor_analyses = len([r for r in self if r['Sample'] in self.anchors]) self.repeatability['r_D47a'] = self.compute_r('D47', samples = 'anchors') self.repeatability['r_D47a'] /= ( (N_anchor_analyses - np.sum([self.sessions[s]['Np'] for s in self.sessions])) / (N_anchor_analyses - len(self.anchors)) )**.5 self.repeatability['r_D47u'] = self.compute_r('D47', samples = 'unknowns') self.repeatability['r_D47'] = self.compute_r('D47', samples = 'all samples') self.repeatability['r_D47'] /= ( (len(self) - len(self.unknowns) - np.sum([self.sessions[s]['Np'] for s in self.sessions])) / (len(self) - len(self.samples)) )**.5 def report(self)-
Prints a report on the standardization fit.
Expand source code
def report(self): ''' Prints a report on the standardization fit. ''' report_fit(self.standardization) def rmswd(self, samples='all samples', sessions='all sessions')-
Compute the root mean squared weighted deviation, χ2 and corresponding degrees of freedom of
[r['D47'] for r in self]Expand source code
@make_verbal def rmswd(self, samples = 'all samples', sessions = 'all sessions', ): ''' Compute the root mean squared weighted deviation, χ2 and corresponding degrees of freedom of `[r['D47'] for r in self]` ''' if samples == 'all samples': mysamples = [k for k in self.samples] elif samples == 'anchors': mysamples = [k for k in self.anchors] elif samples == 'unknowns': mysamples = [k for k in self.unknowns] else: mysamples = samples if sessions == 'all sessions': sessions = [k for k in self.sessions] chisq, Nf = 0, 0 for sample in mysamples : G = [ r for r in self if r['Sample'] == sample and r['Session'] in sessions ] if len(G) > 1 : X, sX = w_avg([r['D47'] for r in G], [r['wD47'] for r in G]) Nf += (len(G) - 1) chisq += np.sum([ ((r['D47']-X)/r['wD47'])**2 for r in G]) r = (chisq / Nf)**.5 if Nf > 0 else 0 self.msg(f'RMSWD of r["D47"] is {r:.6f} for {samples}.') return {'rmswd': r, 'chisq': chisq, 'Nf': Nf} def sample_D47_correl(self, sample1, sample2='')-
Correlation between Δ47 errors of samples
Returns the error correlation between the average Δ47 values of two samples.
Expand source code
def sample_D47_correl(self, sample1, sample2 = ''): ''' Correlation between Δ<sub>47</sub> errors of samples Returns the error correlation between the average Δ47 values of two samples. ''' if sample2 == '' or sample2 == sample1: return 1. return ( self.sample_D47_covar(sample1, sample2) / self.unknowns[sample1]['SE_D47'] / self.unknowns[sample2]['SE_D47'] ) def sample_D47_covar(self, sample1, sample2='')-
Covariance between Δ47 values of samples
Returns the error covariance between the average Δ47 values of two samples. If if only
sample_1is specified, or ifsample_1 == sample_2), returns the Δ47 variance for that sample.Expand source code
def sample_D47_covar(self, sample1, sample2 = ''): ''' Covariance between Δ<sub>47</sub> values of samples Returns the error covariance between the average Δ<sub>47</sub> values of two samples. If if only `sample_1` is specified, or if `sample_1 == sample_2`), returns the Δ<sub>47</sub> variance for that sample. ''' if sample2 == '': sample2 = sample1 if self.standardization_method == 'pooled': i = self.standardization.var_names.index(f'D47_{pf(sample1)}') j = self.standardization.var_names.index(f'D47_{pf(sample2)}') return self.standardization.covar[i, j] elif self.standardization_method == 'indep_sessions': if sample1 == sample2: return self.samples[sample1]['SE_D47']**2 else: c = 0 for session in self.sessions: sdata1 = [r for r in self.sessions[session]['data'] if r['Sample'] == sample1] sdata2 = [r for r in self.sessions[session]['data'] if r['Sample'] == sample2] if sdata1 and sdata2: a = self.sessions[session]['a'] # !! TODO: CM below does not account for temporal changes in standardization parameters CM = self.sessions[session]['CM'][:3,:3] avg_D47_1 = np.mean([r['D47'] for r in sdata1]) avg_d47_1 = np.mean([r['d47'] for r in sdata1]) avg_D47_2 = np.mean([r['D47'] for r in sdata2]) avg_d47_2 = np.mean([r['d47'] for r in sdata2]) c += ( self.unknowns[sample1]['session_D47'][session][2] * self.unknowns[sample2]['session_D47'][session][2] * np.array([[avg_D47_1, avg_d47_1, 1]]) @ CM @ np.array([[avg_D47_2, avg_d47_2, 1]]).T ) / a**2 return float(c) def sample_average(self, samples, weights='equal', normalize=True)-
Weighted average Δ47 value of a group of samples, accounting for covariance.
Returns the weighed average Δ47 value and associated SE of a group of samples. Weights are equal by default. If
normalizeis true,weightswill be rescaled so that their sum equals 1.Examples
self.sample_average(['X','Y'], [1, 2])returns the value and SE of [Δ47(X) + 2 Δ47(Y)]/3, where Δ47(X) and Δ47(Y) are the average Δ47 values of samples X and Y, respectively.
self.sample_average(['X','Y'], [1, -1], normalize = False)returns the value and SE of the difference Δ47(X) - Δ47(Y).
Expand source code
def sample_average(self, samples, weights = 'equal', normalize = True): ''' Weighted average Δ<sub>47</sub> value of a group of samples, accounting for covariance. Returns the weighed average Δ47 value and associated SE of a group of samples. Weights are equal by default. If `normalize` is true, `weights` will be rescaled so that their sum equals 1. __Examples__ ```python self.sample_average(['X','Y'], [1, 2]) ``` returns the value and SE of [Δ<sub>47</sub>(X) + 2 Δ<sub>47</sub>(Y)]/3, where Δ<sub>47</sub>(X) and Δ<sub>47</sub>(Y) are the average Δ<sub>47</sub> values of samples X and Y, respectively. ```python self.sample_average(['X','Y'], [1, -1], normalize = False) ``` returns the value and SE of the difference Δ<sub>47</sub>(X) - Δ<sub>47</sub>(Y). ''' if weights == 'equal': weights = [1/len(samples)] * len(samples) if normalize: s = sum(weights) weights = [w/s for w in weights] try: # indices = [self.standardization.var_names.index(f'D47_{pf(sample)}') for sample in samples] # C = self.standardization.covar[indices,:][:,indices] C = np.array([[self.sample_D47_covar(x, y) for x in samples] for y in samples]) X = [self.samples[sample]['D47'] for sample in samples] return correlated_sum(X, C, weights) except ValueError: return (0., 0.) def split_samples(self, samples_to_split='all', grouping='by_uid')-
Split unknown samples by UID (treat all analyses as different samples) or by session (treat analyses of a given sample in different sessions as different samples).
Parameters
samples_to_split: a list of samples to split, e.g.,['IAEA-C1', 'IAEA-C2']grouping:by_uid|by_session
Expand source code
def split_samples(self, samples_to_split = 'all', grouping = 'by_uid'): ''' Split unknown samples by UID (treat all analyses as different samples) or by session (treat analyses of a given sample in different sessions as different samples). __Parameters__ + `samples_to_split`: a list of samples to split, e.g., `['IAEA-C1', 'IAEA-C2']` + `grouping`: `by_uid` | `by_session` ''' if samples_to_split == 'all': samples_to_split = [s for s in self.unknowns] gkeys = {'by_uid':'UID', 'by_session':'Session'} self.grouping = grouping.lower() if self.grouping in gkeys: gkey = gkeys[self.grouping] for r in self: if r['Sample'] in samples_to_split: r['Sample_original'] = r['Sample'] r['Sample'] = f"{r['Sample']}__{r[gkey]}" elif r['Sample'] in self.unknowns: r['Sample_original'] = r['Sample'] self.refresh_samples() def standardization_error(self, session, d47, D47, t=0)-
Compute standardization error for a given session and (δ47, Δ47) composition.
Expand source code
def standardization_error(self, session, d47, D47, t = 0): ''' Compute standardization error for a given session and (δ<sub>47</sub>, Δ<sub>47</sub>) composition. ''' a = self.sessions[session]['a'] b = self.sessions[session]['b'] c = self.sessions[session]['c'] a2 = self.sessions[session]['a2'] b2 = self.sessions[session]['b2'] c2 = self.sessions[session]['c2'] CM = self.sessions[session]['CM'] x, y = D47, d47 z = a * x + b * y + c + a2 * x * t + b2 * y * t + c2 * t # x = (z - b*y - b2*y*t - c - c2*t) / (a+a2*t) dxdy = -(b+b2*t) / (a+a2*t) dxdz = 1. / (a+a2*t) dxda = -x / (a+a2*t) dxdb = -y / (a+a2*t) dxdc = -1. / (a+a2*t) dxda2 = -x * a2 / (a+a2*t) dxdb2 = -y * t / (a+a2*t) dxdc2 = -t / (a+a2*t) V = np.array([dxda, dxdb, dxdc, dxda2, dxdb2, dxdc2]) sx = (V @ CM @ V.T) ** .5 return sx def standardize(self, method='pooled', weighted_sessions=[], consolidate=True, consolidate_tables=False, consolidate_plots=False)-
Compute absolute Δ47 values for all replicate analyses and for sample averages. If
methodargument is set to'pooled', the standardization processes all sessions in a single step, assuming that all samples (anchors and unknowns alike) are homogeneous (i.e. that their true Δ47 value does not change between sessions). Ifmethodargument is set to'indep_sessions', the standardization processes each session independently, based only on anchors analyses.Expand source code
@make_verbal def standardize(self, method = 'pooled', weighted_sessions = [], consolidate = True, consolidate_tables = False, consolidate_plots = False, ): ''' Compute absolute Δ<sub>47</sub> values for all replicate analyses and for sample averages. If `method` argument is set to `'pooled'`, the standardization processes all sessions in a single step, assuming that all samples (anchors and unknowns alike) are homogeneous (i.e. that their true Δ<sub>47</sub> value does not change between sessions). If `method` argument is set to `'indep_sessions'`, the standardization processes each session independently, based only on anchors analyses. ''' self.standardization_method = method self.assign_timestamps() if method == 'pooled': if weighted_sessions: for session_group in weighted_sessions: X = D47data([r for r in self if r['Session'] in session_group]) result = X.standardize(method = 'pooled', weighted_sessions = [], consolidate = False) w = np.sqrt(result.redchi) self.msg(f'Session group {session_group} MRSWD = {w:.4f}') for r in X: r['wD47raw'] *= w else: self.msg('All D47raw weights set to 1 ‰') for r in self: r['wD47raw'] = 1. params = Parameters() for k,session in enumerate(self.sessions): self.msg(f"Session {session}: scrambling_drift is {self.sessions[session]['scrambling_drift']}.") self.msg(f"Session {session}: slope_drift is {self.sessions[session]['slope_drift']}.") self.msg(f"Session {session}: wg_drift is {self.sessions[session]['wg_drift']}.") s = pf(session) params.add(f'a_{s}', value = 0.9) params.add(f'b_{s}', value = 0.) params.add(f'c_{s}', value = -0.9) params.add(f'a2_{s}', value = 0., vary = self.sessions[session]['scrambling_drift']) params.add(f'b2_{s}', value = 0., vary = self.sessions[session]['slope_drift']) params.add(f'c2_{s}', value = 0., vary = self.sessions[session]['wg_drift']) for sample in self.unknowns: params.add(f'D47_{pf(sample)}', value=0.6) def residuals(p): R = [] for r in self: session = pf(r['Session']) sample = pf(r['Sample']) if r['Sample'] in self.Nominal_D47: R += [ ( r['D47raw'] - ( p[f'a_{session}'] * self.Nominal_D47[r['Sample']] + p[f'b_{session}'] * r['d47'] + p[f'c_{session}'] + r['t'] * ( p[f'a2_{session}'] * self.Nominal_D47[r['Sample']] + p[f'b2_{session}'] * r['d47'] + p[f'c2_{session}'] ) ) ) / r['wD47raw'] ] else: R += [ ( r['D47raw'] - ( p[f'a_{session}'] * p[f'D47_{sample}'] + p[f'b_{session}'] * r['d47'] + p[f'c_{session}'] + r['t'] * ( p[f'a2_{session}'] * p[f'D47_{sample}'] + p[f'b2_{session}'] * r['d47'] + p[f'c2_{session}'] ) ) ) / r['wD47raw'] ] return R M = Minimizer(residuals, params) result = M.leastsq() self.Nf = result.nfree self.t95 = tstudent.ppf(1 - 0.05/2, self.Nf) # if self.verbose: # report_fit(result) for r in self: s = pf(r["Session"]) a = result.params.valuesdict()[f'a_{s}'] b = result.params.valuesdict()[f'b_{s}'] c = result.params.valuesdict()[f'c_{s}'] a2 = result.params.valuesdict()[f'a2_{s}'] b2 = result.params.valuesdict()[f'b2_{s}'] c2 = result.params.valuesdict()[f'c2_{s}'] r['D47'] = (r['D47raw'] - c - b * r['d47'] - c2 * r['t'] - b2 * r['t'] * r['d47']) / (a + a2 * r['t']) self.standardization = result if consolidate: self.consolidate(tables = consolidate_tables, plots = consolidate_plots) return result elif method == 'indep_sessions': if weighted_sessions: for session_group in weighted_sessions: X = D47data([r for r in self if r['Session'] in session_group]) X.Nominal_D47 = self.Nominal_D47.copy() X.refresh() # This is only done to assign r['wD47raw'] for r in X: X.standardize(method = method, weighted_sessions = [], consolidate = False) self.msg(f'D47raw weights set to {1000*X[0]["wD47raw"]:.1f} ppm for sessions in {session_group}') else: self.msg('All weights set to 1 ‰') for r in self: r['wD47raw'] = 1 for session in self.sessions: s = self.sessions[session] p_names = ['a', 'b', 'c', 'a2', 'b2', 'c2'] p_active = [True, True, True, s['scrambling_drift'], s['slope_drift'], s['wg_drift']] s['Np'] = sum(p_active) sdata = s['data'] A = np.array([ [ self.Nominal_D47[r['Sample']] / r['wD47raw'], r['d47'] / r['wD47raw'], 1 / r['wD47raw'], self.Nominal_D47[r['Sample']] * r['t'] / r['wD47raw'], r['d47'] * r['t'] / r['wD47raw'], r['t'] / r['wD47raw'] ] for r in sdata if r['Sample'] in self.anchors ])[:,p_active] # only keep columns for the active parameters Y = np.array([[r['D47raw'] / r['wD47raw']] for r in sdata if r['Sample'] in self.anchors]) s['Na'] = Y.size CM = linalg.inv(A.T @ A) bf = (CM @ A.T @ Y).T[0,:] k = 0 for n,a in zip(p_names, p_active): if a: s[n] = bf[k] # self.msg(f'{n} = {bf[k]}') k += 1 else: s[n] = 0. # self.msg(f'{n} = 0.0') for r in sdata : a, b, c, a2, b2, c2 = s['a'], s['b'], s['c'], s['a2'], s['b2'], s['c2'] r['D47'] = (r['D47raw'] - c - b * r['d47'] - c2 * r['t'] - b2 * r['t'] * r['d47']) / (a + a2 * r['t']) r['wD47'] = r['wD47raw'] / (a + a2 * r['t']) s['CM'] = np.zeros((6,6)) i = 0 k_active = [j for j,a in enumerate(p_active) if a] for j,a in enumerate(p_active): if a: s['CM'][j,k_active] = CM[i,:] i += 1 if not weighted_sessions: w = self.rmswd()['rmswd'] for r in self: r['wD47'] *= w r['wD47raw'] *= w for session in self.sessions: self.sessions[session]['CM'] *= w**2 for session in self.sessions: s = self.sessions[session] s['SE_a'] = s['CM'][0,0]**.5 s['SE_b'] = s['CM'][1,1]**.5 s['SE_c'] = s['CM'][2,2]**.5 s['SE_a2'] = s['CM'][3,3]**.5 s['SE_b2'] = s['CM'][4,4]**.5 s['SE_c2'] = s['CM'][5,5]**.5 if not weighted_sessions: self.Nf = len(self) - len(self.unknowns) - np.sum([self.sessions[s]['Np'] for s in self.sessions]) else: self.Nf = 0 for sg in weighted_sessions: self.Nf += self.rmswd(sessions = sg)['Nf'] self.t95 = tstudent.ppf(1 - 0.05/2, self.Nf) avgD47 = { sample: np.mean([r['D47'] for r in self if r['Sample'] == sample]) for sample in self.samples } chi2 = np.sum([(r['D47'] - avgD47[r['Sample']])**2 for r in self]) rD47 = (chi2/self.Nf)**.5 self.repeatability['sigma_47'] = rD47 if consolidate: self.consolidate(tables = consolidate_tables, plots = consolidate_plots) def standardize_d13C(self)-
Perform δ13C standadization within each session
saccording toself.sessions[s]['d13C_standardization_method'], which is defined by default byD47data.refresh_sessions()as equal toself.d13C_STANDARDIZATION_METHOD, but may be redefined abitrarily at a later stage.Expand source code
def standardize_d13C(self): ''' Perform δ<sup>13</sup>C standadization within each session `s` according to `self.sessions[s]['d13C_standardization_method']`, which is defined by default by `D47data.refresh_sessions()`as equal to `self.d13C_STANDARDIZATION_METHOD`, but may be redefined abitrarily at a later stage. ''' for s in self.sessions: if self.sessions[s]['d13C_standardization_method'] in ['1pt', '2pt']: XY = [(r['d13C_VPDB'], self.Nominal_d13C_VPDB[r['Sample']]) for r in self.sessions[s]['data'] if r['Sample'] in self.Nominal_d13C_VPDB] X,Y = zip(*XY) if self.sessions[s]['d13C_standardization_method'] == '1pt': offset = np.mean(Y) - np.mean(X) for r in self.sessions[s]['data']: r['d13C_VPDB'] += offset elif self.sessions[s]['d13C_standardization_method'] == '2pt': a,b = np.polyfit(X,Y,1) for r in self.sessions[s]['data']: r['d13C_VPDB'] = a * r['d13C_VPDB'] + b def standardize_d18O(self)-
Perform δ18O standadization within each session
saccording toself.ALPHA_18O_ACID_REACTIONandself.sessions[s]['d18O_standardization_method'], which is defined by default byD47data.refresh_sessions()as equal toself.d18O_STANDARDIZATION_METHOD, but may be redefined abitrarily at a later stage.Expand source code
def standardize_d18O(self): ''' Perform δ<sup>18</sup>O standadization within each session `s` according to `self.ALPHA_18O_ACID_REACTION` and `self.sessions[s]['d18O_standardization_method']`, which is defined by default by `D47data.refresh_sessions()`as equal to `self.d18O_STANDARDIZATION_METHOD`, but may be redefined abitrarily at a later stage. ''' for s in self.sessions: if self.sessions[s]['d18O_standardization_method'] in ['1pt', '2pt']: XY = [(r['d18O_VSMOW'], self.Nominal_d18O_VPDB[r['Sample']]) for r in self.sessions[s]['data'] if r['Sample'] in self.Nominal_d18O_VPDB] X,Y = zip(*XY) Y = [(1000+y) * self.R18_VPDB * self.ALPHA_18O_ACID_REACTION / self.R18_VSMOW - 1000 for y in Y] if self.sessions[s]['d18O_standardization_method'] == '1pt': offset = np.mean(Y) - np.mean(X) for r in self.sessions[s]['data']: r['d18O_VSMOW'] += offset elif self.sessions[s]['d18O_standardization_method'] == '2pt': a,b = np.polyfit(X,Y,1) for r in self.sessions[s]['data']: r['d18O_VSMOW'] = a * r['d18O_VSMOW'] + b def summary(self, dir='results', filename='summary.csv', save_to_file=True, print_out=True)-
Print out an/or save to disk a summary of the standardization results.
Parameters
dir: the directory in which to save the tablefilename: the name to the csv file to write tosave_to_file: whether to save the table to diskprint_out: whether to print out the table
Expand source code
@make_verbal def summary(self, dir = 'results', filename = 'summary.csv', save_to_file = True, print_out = True): ''' Print out an/or save to disk a summary of the standardization results. __Parameters__ + `dir`: the directory in which to save the table + `filename`: the name to the csv file to write to + `save_to_file`: whether to save the table to disk + `print_out`: whether to print out the table ''' out = [] out += [['N samples (anchors + unknowns)', f"{len(self.samples)} ({len(self.anchors)} + {len(self.unknowns)})"]] out += [['N analyses (anchors + unknowns)', f"{len(self)} ({len([r for r in self if r['Sample'] in self.anchors])} + {len([r for r in self if r['Sample'] in self.unknowns])})"]] out += [['Repeatability of δ13C_VPDB', f"{1000 * self.repeatability['r_d13C_VPDB']:.1f} ppm"]] out += [['Repeatability of δ18O_VSMOW', f"{1000 * self.repeatability['r_d18O_VSMOW']:.1f} ppm"]] out += [['Repeatability of Δ47 (anchors)', f"{1000 * self.repeatability['r_D47a']:.1f} ppm"]] out += [['Repeatability of Δ47 (unknowns)', f"{1000 * self.repeatability['r_D47u']:.1f} ppm"]] out += [['Repeatability of Δ47 (all)', f"{1000 * self.repeatability['r_D47']:.1f} ppm"]] out += [['Model degrees of freedom', f"{self.Nf}"]] out += [['Student\'s 95% t-factor', f"{self.t95:.2f}"]] out += [['Standardization method', self.standardization_method]] if save_to_file: if not os.path.exists(dir): os.makedirs(dir) with open(f'{dir}/{filename}', 'w') as fid: fid.write(make_csv(out)) if print_out: self.msg('\n' + pretty_table(out, header = 0)) return out def table_of_analyses(self, dir='results', filename='analyses.csv', save_to_file=True, print_out=True)-
Print out an/or save to disk a table of analyses.
Parameters
dir: the directory in which to save the tablefilename: the name to the csv file to write tosave_to_file: whether to save the table to diskprint_out: whether to print out the table
Expand source code
@make_verbal def table_of_analyses(self, dir = 'results', filename = 'analyses.csv', save_to_file = True, print_out = True): ''' Print out an/or save to disk a table of analyses. __Parameters__ + `dir`: the directory in which to save the table + `filename`: the name to the csv file to write to + `save_to_file`: whether to save the table to disk + `print_out`: whether to print out the table ''' out = [['UID','Session','Sample']] extra_fields = [f for f in [('SampleMass','.2f'),('ColdFingerPressure','.1f'),('AcidReactionYield','.3f')] if f[0] in {k for r in self for k in r}] for f in extra_fields: out[-1] += [f[0]] out[-1] += ['d13Cwg_VPDB','d18Owg_VSMOW','d45','d46','d47','d48','d49','d13C_VPDB','d18O_VSMOW','D47raw','D48raw','D49raw','D47'] for r in self: out += [[f"{r['UID']}",f"{r['Session']}",f"{r['Sample']}"]] for f in extra_fields: out[-1] += [f"{r[f[0]]:{f[1]}}"] out[-1] += [ f"{r['d13Cwg_VPDB']:.3f}", f"{r['d18Owg_VSMOW']:.3f}", f"{r['d45']:.6f}", f"{r['d46']:.6f}", f"{r['d47']:.6f}", f"{r['d48']:.6f}", f"{r['d49']:.6f}", f"{r['d13C_VPDB']:.6f}", f"{r['d18O_VSMOW']:.6f}", f"{r['D47raw']:.6f}", f"{r['D48raw']:.6f}", f"{r['D49raw']:.6f}", f"{r['D47']:.6f}" ] if save_to_file: if not os.path.exists(dir): os.makedirs(dir) with open(f'{dir}/{filename}', 'w') as fid: fid.write(make_csv(out)) if print_out: self.msg('\n' + pretty_table(out)) return out def table_of_samples(self, dir='results', filename='samples.csv', save_to_file=True, print_out=True)-
Print out an/or save to disk a table of samples.
Parameters
dir: the directory in which to save the tablefilename: the name to the csv file to write tosave_to_file: whether to save the table to diskprint_out: whether to print out the table
Expand source code
@make_verbal def table_of_samples(self, dir = 'results', filename = 'samples.csv', save_to_file = True, print_out = True): ''' Print out an/or save to disk a table of samples. __Parameters__ + `dir`: the directory in which to save the table + `filename`: the name to the csv file to write to + `save_to_file`: whether to save the table to disk + `print_out`: whether to print out the table ''' out = [['Sample','N','d13C_VPDB','d18O_VSMOW','D47','SE','95% CL','SD','p_Levene']] for sample in self.anchors: out += [[ f"{sample}", f"{self.samples[sample]['N']}", f"{self.samples[sample]['d13C_VPDB']:.2f}", f"{self.samples[sample]['d18O_VSMOW']:.2f}", f"{self.samples[sample]['D47']:.4f}",'','', f"{self.samples[sample]['SD_D47']:.4f}" if self.samples[sample]['N'] > 1 else '', '' ]] for sample in self.unknowns: out += [[ f"{sample}", f"{self.samples[sample]['N']}", f"{self.samples[sample]['d13C_VPDB']:.2f}", f"{self.samples[sample]['d18O_VSMOW']:.2f}", f"{self.samples[sample]['D47']:.4f}", f"{self.samples[sample]['SE_D47']:.4f}", f"± {self.samples[sample]['SE_D47']*self.t95:.4f}", f"{self.samples[sample]['SD_D47']:.4f}" if self.samples[sample]['N'] > 1 else '', f"{self.samples[sample]['p_Levene']:.3f}" if self.samples[sample]['N'] > 2 else '' ]] if save_to_file: if not os.path.exists(dir): os.makedirs(dir) with open(f'{dir}/{filename}', 'w') as fid: fid.write(make_csv(out)) if print_out: self.msg('\n'+pretty_table(out)) return out def table_of_sessions(self, dir='results', filename='sessions.csv', save_to_file=True, print_out=True)-
Print out an/or save to disk a table of sessions.
Parameters
dir: the directory in which to save the tablefilename: the name to the csv file to write tosave_to_file: whether to save the table to diskprint_out: whether to print out the table
Expand source code
@make_verbal def table_of_sessions(self, dir = 'results', filename = 'sessions.csv', save_to_file = True, print_out = True): ''' Print out an/or save to disk a table of sessions. __Parameters__ + `dir`: the directory in which to save the table + `filename`: the name to the csv file to write to + `save_to_file`: whether to save the table to disk + `print_out`: whether to print out the table ''' include_a2 = any([self.sessions[session]['scrambling_drift'] for session in self.sessions]) include_b2 = any([self.sessions[session]['slope_drift'] for session in self.sessions]) include_c2 = any([self.sessions[session]['wg_drift'] for session in self.sessions]) out = [['Session','Na','Nu','d13Cwg_VPDB','d18Owg_VSMOW','r_d13C','r_d18O','r_D47','a ± SE','1e3 x b ± SE','c ± SE']] if include_a2: out[-1] += ['a2 ± SE'] if include_b2: out[-1] += ['b2 ± SE'] if include_c2: out[-1] += ['c2 ± SE'] for session in self.sessions: out += [[ session, f"{self.sessions[session]['Na']}", f"{self.sessions[session]['Nu']}", f"{self.sessions[session]['d13Cwg_VPDB']:.3f}", f"{self.sessions[session]['d18Owg_VSMOW']:.3f}", f"{self.sessions[session]['r_d13C_VPDB']:.4f}", f"{self.sessions[session]['r_d18O_VSMOW']:.4f}", f"{self.sessions[session]['r_D47']:.4f}", f"{self.sessions[session]['a']:.3f} ± {self.sessions[session]['SE_a']:.3f}", f"{1e3*self.sessions[session]['b']:.3f} ± {1e3*self.sessions[session]['SE_b']:.3f}", f"{self.sessions[session]['c']:.3f} ± {self.sessions[session]['SE_c']:.3f}", ]] if include_a2: if self.sessions[session]['scrambling_drift']: out[-1] += [f"{self.sessions[session]['a2']:.1e} ± {self.sessions[session]['SE_a2']:.1e}"] else: out[-1] += [''] if include_b2: if self.sessions[session]['slope_drift']: out[-1] += [f"{self.sessions[session]['b2']:.1e} ± {self.sessions[session]['SE_b2']:.1e}"] else: out[-1] += [''] if include_c2: if self.sessions[session]['wg_drift']: out[-1] += [f"{self.sessions[session]['c2']:.1e} ± {self.sessions[session]['SE_c2']:.1e}"] else: out[-1] += [''] if save_to_file: if not os.path.exists(dir): os.makedirs(dir) with open(f'{dir}/{filename}', 'w') as fid: fid.write(make_csv(out)) if print_out: self.msg('\n' + pretty_table(out)) return out def unsplit_samples(self, tables=True)-
Reverse the effects of
D47data.split_samples().Expand source code
def unsplit_samples(self, tables = True): ''' Reverse the effects of `D47data.split_samples`. ''' unknowns_old = sorted({s for s in self.unknowns}) CM_old = self.standardization.covar[:,:] VD_old = self.standardization.params.valuesdict().copy() vars_old = self.standardization.var_names unknowns_new = sorted({r['Sample_original'] for r in self if 'Sample_original' in r}) Ns = len(vars_old) - len(unknowns_old) vars_new = vars_old[:Ns] + [f'D47_{pf(u)}' for u in unknowns_new] VD_new = {k: VD_old[k] for k in vars_old[:Ns]} W = np.zeros((len(vars_new), len(vars_old))) W[:Ns,:Ns] = np.eye(Ns) for u in unknowns_new: splits = sorted({r['Sample'] for r in self if 'Sample_original' in r and r['Sample_original'] == u}) if self.grouping == 'by_session': weights = [self.samples[s]['SE_D47']**-2 for s in splits] elif self.grouping == 'by_uid': weights = [1 for s in splits] sw = sum(weights) weights = [w/sw for w in weights] W[vars_new.index(f'D47_{pf(u)}'),[vars_old.index(f'D47_{pf(s)}') for s in splits]] = weights[:] # print('\nUnsplitting weights matrix:') # print('\n'.join([' '.join([f'{x:.1f}' if x else ' - ' for x in l]) for l in W])) # print('---') CM_new = W @ CM_old @ W.T V = W @ np.array([[VD_old[k]] for k in vars_old]) VD_new = {k:v[0] for k,v in zip(vars_new, V)} self.standardization.covar = CM_new self.standardization.params.valuesdict = lambda : VD_new self.standardization.var_names = vars_new for r in self: if r['Sample'] in self.unknowns: r['Sample_split'] = r['Sample'] r['Sample'] = r['Sample_original'] self.refresh_samples() self.consolidate_samples() self.repeatabilies() if tables: self.table_of_analyses() self.table_of_samples() def vmsg(self, txt)-
Log a message to
self.logfileand print it outExpand source code
def vmsg(self, txt): ''' Log a message to `self.logfile` and print it out ''' self.log(txt) print(txt) def wg(self, samples='', a18_acid='')-
Compute bulk composition of the working gas for each session based on the carbonate standards defined both in
self.Nominal_d13C_VPDBand inself.Nominal_d18O_VPDB.Expand source code
@make_verbal def wg(self, samples = '', a18_acid = ''): ''' Compute bulk composition of the working gas for each session based on the carbonate standards defined both in `self.Nominal_d13C_VPDB` and in `self.Nominal_d18O_VPDB`. ''' self.msg('Computing WG composition:') if a18_acid == '': a18_acid = self.ALPHA_18O_ACID_REACTION if samples == '': samples = [s for s in self.Nominal_d13C_VPDB if s in self.Nominal_d18O_VPDB] assert a18_acid, f'Acid fractionation value should differ from zero.' samples = [s for s in samples if s in self.Nominal_d13C_VPDB and s in self.Nominal_d18O_VPDB] R45R46_standards = {} for sample in samples: d13C_vpdb = self.Nominal_d13C_VPDB[sample] d18O_vpdb = self.Nominal_d18O_VPDB[sample] R13_s = self.R13_VPDB * (1 + d13C_vpdb / 1000) R17_s = self.R17_VPDB * ((1 + d18O_vpdb / 1000) * a18_acid) ** self.lambda_17 R18_s = self.R18_VPDB * (1 + d18O_vpdb / 1000) * a18_acid C12_s = 1 / (1 + R13_s) C13_s = R13_s / (1 + R13_s) C16_s = 1 / (1 + R17_s + R18_s) C17_s = R17_s / (1 + R17_s + R18_s) C18_s = R18_s / (1 + R17_s + R18_s) C626_s = C12_s * C16_s ** 2 C627_s = 2 * C12_s * C16_s * C17_s C628_s = 2 * C12_s * C16_s * C18_s C636_s = C13_s * C16_s ** 2 C637_s = 2 * C13_s * C16_s * C17_s C727_s = C12_s * C17_s ** 2 R45_s = (C627_s + C636_s) / C626_s R46_s = (C628_s + C637_s + C727_s) / C626_s R45R46_standards[sample] = (R45_s, R46_s) for s in self.sessions: db = [r for r in self.sessions[s]['data'] if r['Sample'] in samples] assert db, f'No sample from {samples} found in session "{s}".' # dbsamples = sorted({r['Sample'] for r in db}) X = [r['d45'] for r in db] Y = [R45R46_standards[r['Sample']][0] for r in db] x1, x2 = np.min(X), np.max(X) wgcoord = x1/(x1-x2) if wgcoord < -.5 or wgcoord > 1.5: # unreasonable to extrapolate to d45 = 0 R45_wg = np.mean([y/(1+x/1000) for x,y in zip(X,Y)]) else : # d45 = 0 is reasonably well bracketed R45_wg = np.polyfit(X, Y, 1)[1] X = [r['d46'] for r in db] Y = [R45R46_standards[r['Sample']][1] for r in db] x1, x2 = np.min(X), np.max(X) wgcoord = x1/(x1-x2) if wgcoord < -.5 or wgcoord > 1.5: # unreasonable to extrapolate to d46 = 0 R46_wg = np.mean([y/(1+x/1000) for x,y in zip(X,Y)]) else : # d46 = 0 is reasonably well bracketed R46_wg = np.polyfit(X, Y, 1)[1] d13Cwg_VPDB, d18Owg_VSMOW = self.compute_bulk_delta(R45_wg, R46_wg) self.msg(f'Session {s} WG: δ13C_VPDB = {d13Cwg_VPDB:.3f} δ18O_VSMOW = {d18Owg_VSMOW:.3f}') self.sessions[s]['d13Cwg_VPDB'] = d13Cwg_VPDB self.sessions[s]['d18Owg_VSMOW'] = d18Owg_VSMOW for r in self.sessions[s]['data']: r['d13Cwg_VPDB'] = d13Cwg_VPDB r['d18Owg_VSMOW'] = d18Owg_VSMOW def wg_old(self, sample='', d13C_vpdb='', d18O_vpdb='', a18_acid='')-
Compute bulk composition of the working gas for each session based on the average composition, within each session, of a given sample.
Expand source code
@make_verbal def wg_old(self, sample = '', d13C_vpdb = '', d18O_vpdb = '', a18_acid = ''): ''' Compute bulk composition of the working gas for each session based on the average composition, within each session, of a given sample. ''' self.msg('Computing WG composition:') if sample == '': sample = self.SAMPLE_CONSTRAINING_WG_COMPOSITION[0] if d13C_vpdb == '': d13C_vpdb = self.SAMPLE_CONSTRAINING_WG_COMPOSITION[1] if d18O_vpdb == '': d18O_vpdb = self.SAMPLE_CONSTRAINING_WG_COMPOSITION[2] if a18_acid == '': a18_acid = self.ALPHA_18O_ACID_REACTION assert a18_acid, f'Acid fractionation value should differ from zero.' R13_s = self.R13_VPDB * (1 + d13C_vpdb / 1000) R17_s = self.R17_VPDB * ((1 + d18O_vpdb / 1000) * a18_acid) ** self.lambda_17 R18_s = self.R18_VPDB * (1 + d18O_vpdb / 1000) * a18_acid C12_s = 1 / (1 + R13_s) C13_s = R13_s / (1 + R13_s) C16_s = 1 / (1 + R17_s + R18_s) C17_s = R17_s / (1 + R17_s + R18_s) C18_s = R18_s / (1 + R17_s + R18_s) C626_s = C12_s * C16_s ** 2 C627_s = 2 * C12_s * C16_s * C17_s C628_s = 2 * C12_s * C16_s * C18_s C636_s = C13_s * C16_s ** 2 C637_s = 2 * C13_s * C16_s * C17_s C727_s = C12_s * C17_s ** 2 R45_s = (C627_s + C636_s) / C626_s R46_s = (C628_s + C637_s + C727_s) / C626_s for s in self.sessions: db = [r for r in self.sessions[s]['data'] if r['Sample'] == sample] assert db, f'Sample "{sample}" not found in session "{s}".' d45_s = np.mean([r['d45'] for r in db]) d46_s = np.mean([r['d46'] for r in db]) R45_wg = R45_s / (1 + d45_s / 1000) R46_wg = R46_s / (1 + d46_s / 1000) d13Cwg_VPDB, d18Owg_VSMOW = self.compute_bulk_delta(R45_wg, R46_wg) self.msg(f'Session {s} WG: δ13C_VPDB = {d13Cwg_VPDB:.3f} δ18O_VSMOW = {d18Owg_VSMOW:.3f}') self.sessions[s]['d13Cwg_VPDB'] = d13Cwg_VPDB self.sessions[s]['d18Owg_VSMOW'] = d18Owg_VSMOW for r in self.sessions[s]['data']: r['d13Cwg_VPDB'] = d13Cwg_VPDB r['d18Owg_VSMOW'] = d18Owg_VSMOW
class SessionPlot-
Expand source code
class SessionPlot(): def __init__(self): pass