Usage | Load the data | Fit the correction | Inspect the fit | Run-to-run scatter and diagnostics | Method: the decomposition | The physical effect and the forward model | Separating the components by PCA | Estimating the common kappa | Drift and the daily factor (NA-tolerant imputation) | Refining the centre: chi-square minimisation | Change points: episode and precision breaks | References
Package: appac 4.0.3
Ruediger Forster
appac: Atmospheric Pressure Peak Area Correction for Gas Chromatography with Standard Detectors
Corrects gas-chromatography peak areas for the influence of ambient air pressure on standard detectors open to the ambient atmosphere, such as the flame ionization detector, whose pressure sensitivity was characterised by Bocek, Novak and Janak (1969) <doi:10.1016/S0021-9673(00)99223-9>. Unlike the pressure compensation of Ayers and Clardy (1985) <https://patents.google.com/patent/US4512181A>, which is combined with a calibration and valid only for a single calibration period of a few days, per-cylinder peak areas are decomposed by principal components into a pressure-correlated component and per-peak drift; a common pressure-sensitivity coefficient (kappa) is estimated with a heavy-tail-robust fit on a drift-reduced signal, and slow drift plus a daily factor are removed. Returns the corrected areas together with a chi-square goodness-of-fit diagnostic. Structural-break detection (package 'strucchange', Zeileis and others (2002) <doi:10.18637/jss.v007.i02>) is provided for episode-level and variance breakpoint analysis.
Authors:
appac_4.0.3.tar.gz
appac_4.0.3.tar.gz(r-4.7-any)appac_4.0.3.tar.gz(r-4.6-any)
appac_4.0.3.tgz(r-4.6-emscripten)
manual.pdf |manual.html✨
DESCRIPTION |NEWS
card.svg |card.png
appac/json (API)
| # Install 'appac' in R: |
| install.packages('appac', repos = c('https://cran.r-universe.dev', 'https://cloud.r-project.org')) |
Datasets:
- PLOT_FID - Flame-ionization-detector peak areas for APPAC
- Synth_data - Synthetic stress-test data for APPAC
This package does not link to any Github/Gitlab/R-forge repository. No issue tracker or development information is available.
Last updated from:546b3d4f3b. Checks:4 OK. Indexed: yes.
| Target | Result | Time | Files | Syslog |
|---|---|---|---|---|
| linux-devel-x86_64 | OK | 143 | ||
| source / vignettes | OK | 208 | ||
| linux-release-x86_64 | OK | 143 | ||
| wasm-release | OK | 142 |
Exports:appaccheck_colsdebias_ctget_changepointsget_variance_changepointsgoodness_of_fitplot_area_dateplot_area_pressureplot_area_pressure_fitplot_residualsprintshow
Dependencies:clidata.tableDEoptimRdplyrgenericsgluekzalatticelifecyclemagrittrpillarpkgconfigpurrrR6rlangrobustbasesandwichstrucchangetibbletidyselectutf8vctrswithrzoo
Readme and manuals
Help Manual
| Help page | Topics |
|---|---|
| Fit the APPAC pressure correction | appac |
| Fitted APPAC model | Appac-class print,Appac-method show,Appac-method |
| Validate and canonicalise the input columns | check_cols |
| Drift / daily-factor model | Compensation-class show,Compensation-method |
| Pressure correction model | Correction-class show,Correction-method |
| De-bias the per-peak centres | debias_ct |
| Detect episode level breakpoints across cylinders | get_changepoints |
| Detect variance breakpoints across cylinders | get_variance_changepoints |
| Goodness of fit of the correction | goodness_of_fit |
| Plot peak area versus date | plot_area_date |
| Plot peak area versus air pressure | plot_area_pressure |
| Plot the kappa-fit input | plot_area_pressure_fit |
| Flame-ionization-detector peak areas for APPAC | PLOT_FID |
| Residual diagnostic panel | plot_residuals |
| Synthetic stress-test data for APPAC | Synth_data |