catregs (version 1.3)

count.fit: Fits four different count models and compares them.

Description

Given a Poisson model object, count.fit fits Poisson, negative binomial, zero-inflated Poisson, and zero-inflated negative binomial models to the data. It reports results of Vuong tests between the zero-inflated and non-zer-inflated models, summarizes the information criteria of the four models, summarizes the model output of the four models, creates a ggplot object of coefficient plots for each model, and creates a ggplot object of model residuals.

Usage

count.fit(m1,y.range,rounded=3,use.color="yes")

Value

ic

A data.frame summarizing the information criteria for the four models. Bayesian and Akaike's informaiton criteria are included.

models

A summary of the model estimates, including coefficients and standard errors.

pic

A ggplot object illustrating model residuals for each type of model.

models.pic

A ggplot object of coefficient plots from each type of model.

Arguments

m1

A Poisson regression model, as estimated via the glm function.

y.range

The observed response range for the count outcome. For example, if the observed range is 0 to 18, this would be 0:18

rounded

The number of decimal places to round the output. The default is 3.

use.color

Whether to use color in the ggplot objects. Default is "yes"

Author

David Melamed

Examples

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)