Package: douconca
Type: Package
Title: Double Constrained Correspondence Analysis for Trait-Environment
        Analysis in Ecology
Version: 1.2.5
Date: 2026-02-23
Authors@R: c(person(given = "Cajo J.F", 
                    family = "ter Braak", 
                    email = "cajo.terbraak@wur.nl",
                    role = "aut", 
                    comment = c(ORCID = "0000-0002-0414-8745")),
            person(given = "Bart-Jan", 
                   family = "van Rossum", 
                   email = "bart-jan.vanrossum@wur.nl", 
                   role = c("aut", "cre"),
                   comment = c(ORCID = "0000-0002-8673-2514")))
Description: Double constrained correspondence analysis (dc-CA)
        analyzes (multi-)trait (multi-)environment ecological data by
        using the 'vegan' package and native R code. Throughout the two
        step algorithm of ter Braak et al. (2018) is used. This
        algorithm combines and extends community- (sample-) and
        species-level analyses, i.e. the usual community weighted means
        (CWM)-based regression analysis and the species-level analysis
        of species-niche centroids (SNC)-based regression analysis. The
        two steps use canonical correspondence analysis to regress the
        abundance data on to the traits and (weighted) redundancy
        analysis to regress the CWM of the orthonormalized traits on to
        the environmental predictors. The function dc_CA() has an
        option to divide the abundance data of a site by the site
        total, giving equal site weights. This division has the
        advantage that the multivariate analysis corresponds with an
        unweighted (multi-trait) community-level analysis, instead of
        being weighted. The first step of the algorithm uses
        vegan::cca(). The second step uses wrda() but vegan::rda() if
        the site weights are equal. This version has a predict()
        function. For details see ter Braak et al. 2018
        <doi:10.1007/s10651-017-0395-x>. and ter Braak & van Rossum
        2025 <doi:10.1016/j.ecoinf.2025.103143>.
Depends: R (>= 4.0.0)
License: GPL-3
Encoding: UTF-8
LazyData: true
Imports: ggplot2 (>= 3.5.1), ggrepel, gridExtra, permute, rlang, stats,
        vegan (>= 2.6-8)
RoxygenNote: 7.3.3
NeedsCompilation: no
Suggests: rmarkdown, knitr, tinytest
VignetteBuilder: knitr
URL: https://zenodo.org/records/13970152,
        https://github.com/Biometris/douconca
BugReports: https://github.com/Biometris/douconca/issues
Repository: https://biometris.r-universe.dev
Date/Publication: 2026-02-23 12:48:12 UTC
RemoteUrl: https://github.com/biometris/douconca
RemoteRef: HEAD
RemoteSha: b56e98d23c3c52d872a7a03fb150dd97196015b6
Packaged: 2026-06-23 07:21:05 UTC; root
Author: Cajo J.F ter Braak [aut] (ORCID:
    <https://orcid.org/0000-0002-0414-8745>),
  Bart-Jan van Rossum [aut, cre] (ORCID:
    <https://orcid.org/0000-0002-8673-2514>)
Maintainer: Bart-Jan van Rossum <bart-jan.vanrossum@wur.nl>