---
title: "count.fit"
output: rmarkdown::html_vignette
description: >
  This vignette explains the rationale and implementation for the count.fit function.
vignette: >
  %\VignetteIndexEntry{count.fit}
  %\VignetteEngine{knitr::rmarkdown}
  %\VignetteEncoding{UTF-8}
---

This function compares four models for count responses, namely Poisson regression, negative binomial regression, zero-inflated Poisson regression, and zero-inflated negative binomial regression. To do so, it takes a Poisson regression model object (as specified via glm), and the range on the count outcome. This function mimics the countfit function developed in Long and Freese (2006).

For example:
```{r}
library(catregs)
data("LF06art")
p1 <- glm(art ~ fem + mar + kid5 + phd + ment , family = "poisson", data = LF06art)
table(LF06art$art)
fit<-count.fit(p1,0:19)
names(fit)
#fit$ic
#fit$pic
#fit$models
#fit$models.pic
```