Package: appac
Title: Atmospheric Pressure Peak Area Correction for Gas Chromatography
        with Standard Detectors
Version: 4.0.3
Authors@R: 
    person("Ruediger", "Forster", , "meticulous.measurements@gmail.com",
           role = c("aut", "cre"),
           comment = c(ORCID = "0009-0006-4851-7430"))
Description: 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.
License: GPL-3
Encoding: UTF-8
Depends: R (>= 4.0.0)
Imports: methods, stats, utils, data.table, dplyr, tibble, purrr, kza,
        robustbase, strucchange
Suggests: ggplot2, patchwork, knitr, rmarkdown, testthat (>= 3.0.0)
VignetteBuilder: knitr
Config/testthat/edition: 3
LazyData: true
Config/roxygen2/version: 8.0.0
NeedsCompilation: no
Packaged: 2026-10-01 11:22:26 UTC; root
Author: Ruediger Forster [aut, cre] (ORCID:
        <https://orcid.org/0009-0006-4851-7430>)
Maintainer: Ruediger Forster <meticulous.measurements@gmail.com>
Config/pak/sysreqs: libfftw3-dev
Repository: https://ruedigerforster.r-universe.dev
Date/Publication: 2026-07-15 18:00:02 UTC
RemoteUrl: https://github.com/cran/appac
RemoteRef: HEAD
RemoteSha: 546b3d4f3b7cb6bde362fd9f1b223baa1d5d0d4f
