Species Richness and Extrapolation R package sprex version 1.4.3 Functions for calculating species richness for rarefaction and extrapolation, primarily non-parametric species richness such as jackknife, Chao1, and ACE. Also available are functions for plotting species richness and extrapolation curves, and computing standard diversity and entropy indices. Software Depends: R (>= 4.1.0) Imports: ggplot2, stats, swfscMisc (>= 1.4) Eric Archer <eric.ivan.archer@gmail.com> Comprehensive R Archive Network (CRAN) Eric Archer [aut, cre] GNU General Public License 2025-06-10 application/tgz https://CRAN.R-project.org/package=sprex doi:10.32614/CRAN.package.sprex