Factor out logic
    and math common to Item Factor Analysis fitting, diagnostics, and
    analysis. It is envisioned as core support code suitable for more
    specialized IRT packages to build upon. Complete access to optimized C
    functions are made available with R_RegisterCCallable().
    This software is described in Pritikin & Falk (2020) <doi:10.1177/0146621620929431>.

An enhanced version of the semi-empirical, spatially distributed
    emission and transport model PhosFate implemented in 'R' and 'C++'. It
    currently supports suspended solids (SS) and particulate phosphorus (PP). A
    major feature is the allocation of substance loads entering surface waters
    to their sources of origin, which is a basic requirement for the
    identification of critical source areas and in consequence a cost-effective
    implementation of mitigation measures. References: Hepp et al. (2022)
    <doi:10.1016/j.jenvman.2022.114514>; Hepp and Zessner (2019)
    <doi:10.3390/w11102161>; Kovacs (2013)
    <http://hdl.handle.net/20.500.12708/9468>.

Tools for performing phylogenetic comparative methods for datasets with with multiple observations per species (intraspecific variation or measurement error) and/or missing data (Goolsby et al. 2017). Performs ancestral state reconstruction and missing data imputation on the estimated evolutionary model, which can be specified as Brownian Motion, Ornstein-Uhlenbeck, Early-Burst, Pagel's lambda, kappa, or delta, or a star phylogeny.

Work with the PhyloPic Web Service (<http://api-docs.phylopic.org/v2/>) 
    to fetch silhouette images of organisms. Includes functions for adding 
    silhouettes to both base R plots and ggplot2 plots.

Get information (boards, pins and
    users) from the Pinterest <http://www.pinterest.com>
    API.

Build powerful pivot tables (aka Pivot Grid, Pivot Chart, Cross-Tab)
    and dynamically slice & dice / drag 'n' drop your data. 'rpivotTable' is a
    wrapper of 'pivottable', a powerful open-source Pivot Table library implemented
    in 'JavaScript' by Nicolas Kruchten. Aligned to 'pivottable' v2.19.0.