skellam: The Skellam Distribution: Densities, Sampling, Estimation and Regression

Density, distribution function, quantile function and random generation for the Skellam distribution, the distribution of the difference of two independent Poisson variables (Skellam, 1946), with saddlepoint approximations, maximum likelihood estimation, and a regression model in which both rates depend on covariates. The distribution functions remain accurate for very large rates and far into the tails, on the natural and the log scale.

Version:	0.2.5
Imports:	stats
Suggests:	knitr, rmarkdown, testthat (≥ 3.0.0)
Enhances:	VGAM
Published:	2026-11-09
DOI:	10.32614/CRAN.package.skellam
Author:	Jerry W. Lewis [aut], Patrick E. Brown [aut], Michail Tsagris [aut], Montasser Ghachem [aut, cre], Oguz Ersan [aut]
Maintainer:	Montasser Ghachem <mg at pinstimation.com>
BugReports:	https://github.com/monty-se/skellam/issues
License:	GPL-2 | GPL-3 [expanded from: GPL (≥ 2)]
URL:	https://monty-se.github.io/skellam/, https://github.com/monty-se/skellam
NeedsCompilation:	no
Citation:	skellam citation info
Materials:	README, NEWS
In views:	Distributions
CRAN checks:	skellam results

Documentation:

Reference manual:	skellam.html , skellam.pdf
Vignettes:	Validating the skellam package (source, R code)

Downloads:

Package source:	skellam_0.2.5.tar.gz
Windows binaries:	r-devel: skellam_0.2.4.zip, r-release: skellam_0.2.5.zip, r-oldrel: skellam_0.2.5.zip
macOS binaries:	r-release (arm64): skellam_0.2.5.tgz, r-oldrel (arm64): skellam_0.2.5.tgz, r-release (x86_64): skellam_0.2.5.tgz, r-oldrel (x86_64): skellam_0.2.5.tgz
Old sources:	skellam archive

Reverse dependencies:

Reverse imports:	PINstimation
Reverse suggests:	CCd, extraDistr, fitteR

Linking:

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