Introduction

The Zelig team is pleased to announce the alpha release of Zelig version 4. This suite of R packages offers a user-interface identical to previous Zelig versions while simplifying the developer API and improving core functionality. For specifics concerning changes, see below or read the new Zelig Manual.

What's coming up in Zelig 4's beta release

Improved robust error estimates for simple generalized linear models
Context-sensitive setx parameter passing
Improved bootstrapping support for the developer application programming interface
Support for specifying values of iteraction terms within the setx method call
Improved support for nonstandard formula objects
Additional documentation and additonal frequently asked questions

What's new in Zelig 4

Separation of zelig core from contributed models
An improved toolkit for rapid development of new Zelig models
Package construction wizard (zelig.skeleton)
zelig2 methods support an all-new, simplfied programming style
param methods support a sleeker, more formalized programming style
describe methods now run with less overhead
Brand new hook API, replacing previous zelig3 and zelig4 methods
Test coverage for all models
Integrated numerical and combinatorial math libraries
Roxygen-compliant documentation
Tools for publishing the complete Zelig documentation

Get involved

Install the alpha version and send us any feedback
Read the complete documentation
Read the developer documentation
Port one of the remaining models
Contribute examples, documentation and tips to the Zelig wiki
Contact the Zelig core team for collaboration opportunities

How to Install

Any of the following methods will install Zelig 4 on your current system:

Type source("http://r.iq.harvard.edu/install_live.R") from within an R terminal to interactively select which R packages to download.
Type source("http://r.iq.harvard.edu/install_zelig.R") from within an R terminal to install all Zelig packages.
Follow the installation guide
Download the latest archived build and install, following the instructions within the Installation and Administration Guide

Contact

For information concerning Zelig add-on packages and collaboration opportunities, contact:

Models Already Ported (by package)

Zelig core (Code, Issue Queue)
Models: gamma, logit, ls, negbinom, normal, poisson, probit
Multivariate Regressions (Code, Issue Queue)
Models: blogit, bprobit
Generalized Additive Models (GAM) Regressions (Code, Issue Queue)
Models: logit.gam, normal.gam, poisson.gam, probit.gam
Generalized Estimating Equations (GEE) Regressions (Code, Issue Queue)
Models: gamma.gee, logit.gee, normal.gee, poisson.gee, probit.gee
Mixed Effect Regressions (Code, Issue Queue)
Models: gamma.mixed, logit.mixed, ls.mixed, poisson.mixed, probit.mixed
Multinomial Regressions (Code, Issue Queue)
Models: mlogit, mprobit
Ordinal Regressions (Code, Issue Queue)
Models: ologit, oprobit
Survey-Weighted Regressions (Code, Issue Queue)
Models: gamma.survey, logit.survey, normal.survey, poisson.survey, probit.survey
Bayesian Regressions (Code, Issue Queue)
Models: factor.bayes, logit.bayes, mlogit.bayes, normal.bayes, oprobit,bayes, poisson.bayes, probit.bayes, poisson.bayes
Least Squares Regressions (Code, Issue Queue)
Miscellaneous Extensions: aov, sur

Multiple Stage: twosls, threesls
Network Regressions (Code, Issue Queue)
Models: cloglog.net, gamma.net, logit.net, ls.net, normal.net, poisson.net, probit.net
Common Models (Code, Issue Queue)
Models: exp, lognorm, quantile, relogit, rq, tobit
Miscellaneous (Code, Issue Queue)
Models: arima, coxph, ei.RxC