Package: pscl 1.6.0

Simon Jackman

pscl: Political Science Computational Laboratory

Bayesian analysis of item-response theory (IRT) models, roll call analysis; computing highest density regions; maximum likelihood estimation of zero-inflated and hurdle models for count data; goodness-of-fit measures for GLMs; data sets used in writing and teaching; seats-votes curves.

Authors:Simon Jackman [aut, cre], Alex Tahk [ctb], Achim Zeileis [ctb], Christina Maimone [ctb], James Fearon [ctb], Zoe Meers [ctb]

pscl_1.6.0.tar.gz
pscl_1.6.0.zip(r-4.7)pscl_1.6.0.zip(r-4.6)pscl_1.6.0.zip(r-4.5)
pscl_1.6.0.tgz(r-4.6-x86_64)pscl_1.6.0.tgz(r-4.6-arm64)pscl_1.6.0.tgz(r-4.5-x86_64)pscl_1.6.0.tgz(r-4.5-arm64)
pscl_1.6.0.tar.gz(r-4.7-arm64)pscl_1.6.0.tar.gz(r-4.7-x86_64)pscl_1.6.0.tar.gz(r-4.6-arm64)pscl_1.6.0.tar.gz(r-4.6-x86_64)
pscl_1.6.0.tgz(r-4.6-emscripten)
manual.pdf |manual.html✨
card.svg |card.png
pscl/json (API)

# Install 'pscl' in R:

install.packages('pscl', repos = c('https://atahk.r-universe.dev', 'https://cloud.r-project.org'))

Bug tracker:https://github.com/atahk/pscl/issues

Uses libs:

openmp– GCC OpenMP (GOMP) support library

Datasets:

absentee - Absentee and Machine Ballots in Pennsylvania State Senate Races
admit - Applications to a Political Science PhD Program
AustralianElectionPolling - Political opinion polls in Australia, 2004-07
AustralianElections - Elections to Australian House of Representatives, 1949-2016
bioChemists - Article production by graduate students in biochemistry Ph.D. programs
ca2006 - California Congressional Districts in 2006
EfronMorris - Batting Averages for 18 major league baseball players, 1970
iraqVote - U.S. Senate vote on the use of force against Iraq, 2002.
nj07 - Rollcall object, National Journal key votes of 2007
partycodes - Political parties appearing in the U.S. Congress
politicalInformation - Interviewer ratings of respondent levels of political information
presidentialElections - Elections for U.S. President, 1932-2016, by state
prussian - Prussian army horse kick data
RockTheVote - Voter turnout experiment, using Rock The Vote ads
s109 - Rollcall object, 109th U.S. Senate (2005-06).
sc9497 - Votes from the United States Supreme Court, from 1994-1997
state.info - Information about the American states needed for U.S. Congress
UKHouseOfCommons - 1992 United Kingdom electoral returns
unionDensity - Cross national rates of trade union density
vote92 - Reports of voting in the 1992 U.S. Presidential election.

On CRAN:

openmp

13.58 score 74 stars 58 packages 3.8k scripts 39k downloads 185 mentions 37 exports 1 dependencies

Last updated from:dd72d8e235. Checks:7 WARNING, 6 OK. Indexed: yes.

Target	Result	Time
linux-devel-arm64	WARNING	162
linux-devel-x86_64	WARNING	149
source / vignettes	OK	223
linux-release-arm64	WARNING	141
linux-release-x86_64	WARNING	143
macos-release-arm64	OK	202
macos-release-x86_64	OK	229
macos-oldrel-arm64	OK	198
macos-oldrel-x86_64	OK	266
windows-devel	WARNING	159
windows-release	WARNING	157
windows-oldrel	WARNING	173
wasm-release	OK	113

Exports:betaHPD computeMargins constrain.items constrain.legis convertCodes densigamma dropRollCall dropUnanimous extractRollCallObject hitmiss hurdle hurdle.control hurdletest ideal idealToMCMC igammaHDR ntable odTest pigamma plot.ideal plot.predict.ideal plot.seatsVotes postProcess pR2 predprob qigamma readKH rigamma rollcall seatsVotes simpi summary.rollcall tracex vectorRepresentation vuong zeroinfl zeroinfl.control

Dependencies:MASS

Regression Models for Count Data in R

Rendered fromcountreg.Rnwusingutils::Sweaveon May 20 2026.

Last update: 2026-04-20
Started: 2017-05-04

Citation

Development and contributors

Readme and manuals

Help Manual

Help page	Topics
Absentee and Machine Ballots in Pennsylvania State Senate Races	absentee
Applications to a Political Science PhD Program	admit
Political opinion polls in Australia, 2004-07	AustralianElectionPolling
elections to Australian House of Representatives, 1949-2016	AustralianElections
compute and optionally plot beta HDRs	betaHPD
article production by graduate students in biochemistry Ph.D. programs	bioChemists
California Congressional Districts in 2006	ca2006
add information about voting outcomes to a rollcall object	computeMargins
constrain item parameters in analysis of roll call data	constrain.items
constrain legislators' ideal points in analysis of roll call data	constrain.legis
convert entries in a rollcall matrix to binary form	convertCodes
drop user-specified elements from a rollcall object	dropRollCall
drop unanimous votes from rollcall objects and matrices	dropUnanimous
Batting Averages for 18 major league baseball players, 1970	EfronMorris
return the roll call object used in fitting an ideal model	extractRollCallObject
Table of Actual Outcomes against Predicted Outcomes for discrete data models	hitmiss hitmiss.glm
Hurdle Models for Count Data Regression	hurdle print.hurdle
Control Parameters for Hurdle Count Data Regression	hurdle.control
Testing for the Presence of a Zero Hurdle	hurdletest
analysis of educational testing data and roll call data with IRT models, via Markov chain Monte Carlo methods	ideal
convert an object of class ideal to a coda MCMC object	idealToMCMC
inverse-Gamma distribution	densigamma igamma igammaHDR pigamma qigamma rigamma
U.S. Senate vote on the use of force against Iraq, 2002.	iraqVote
rollcall object, National Journal key votes of 2007	nj07
nicely formatted tables	ntable
likelihood ratio test for over-dispersion in count data	odTest
political parties appearing in the U.S. Congress	partycodes
plots an ideal object	plot.ideal plot1d plot2d
plot methods for predictions from ideal objects	plot.predict.ideal
plot seats-votes curves	plot.seatsVotes
Interviewer ratings of respondent levels of political information	politicalInformation
remap MCMC output via affine transformations	postProcess
compute various pseudo-R2 measures	pR2
Methods for hurdle Objects	coef.hurdle extractAIC.hurdle fitted.hurdle logLik.hurdle model.matrix.hurdle predict.hurdle predprob.hurdle print.summary.hurdle residuals.hurdle summary.hurdle terms.hurdle vcov.hurdle
predicted probabilities from an ideal object	predict.ideal print.predict.ideal
Methods for zeroinfl Objects	coef.zeroinfl extractAIC.zeroinfl fitted.zeroinfl logLik.zeroinfl model.matrix.zeroinfl predict.zeroinfl predprob.zeroinfl print.summary.zeroinfl residuals.zeroinfl summary.zeroinfl terms.zeroinfl vcov.zeroinfl
compute predicted probabilities from fitted models	predprob
Predicted Probabilities for GLM Fits	predprob.glm
predicted probabilities from fitting ideal to rollcall data	predprob.ideal
elections for U.S. President, 1932-2016, by state	presidentialElections
Prussian army horse kick data	prussian
read roll call data in Poole-Rosenthal KH format	readKH
Voter turnout experiment, using Rock The Vote ads	RockTheVote
create an object of class rollcall	rollcall
rollcall object, 109th U.S. Senate (2005-06).	s109
votes from the United States Supreme Court, from 1994-1997	sc9497
A class for creating seats-votes curves	seatsVotes
Monte Carlo estimate of pi (3.14159265...)	simpi
information about the American states needed for U.S. Congress	state.info
summary of an ideal object	summary.ideal
summarize a rollcall object	print.summary.rollcall summary.rollcall
trace plot of MCMC iterates, posterior density of legislators' ideal points	tracex
1992 United Kingdom electoral returns	UKHouseOfCommons
cross national rates of trade union density	unionDensity
convert roll call matrix to series of vectors	vectorRepresentation
Reports of voting in the 1992 U.S. Presidential election.	vote92
Vuong's non-nested hypothesis test	vuong
Zero-inflated Count Data Regression	print.zeroinfl zeroinfl
Control Parameters for Zero-inflated Count Data Regression	zeroinfl.control