summary.zeroinfl: summary of zero-inflated regression models for count data

Description

Summary of zero-inflated regression models for count data.

Usage

## S3 method for class 'zeroinfl':
summary(object, ...)
  ## S3 method for class 'summary.zeroinfl':
print(x,
                digits = max(3, getOption("digits") - 3),
                ...)

Arguments

object

an object of class "zeroinfl", usually a result of a call to zeroinfl

an object of class "summary.zeroinfl", usually a result of a call to summary.zeroinfl

digits

the number of significant digits to use when printing

...

further arguments passed to or from other methods

Value

The function summary.zeroinfl computes and returns a list of summary statistics from the zero-inflated regression model, including
coefficentsa matrix, with columns for the MLEs, their standard errors, $z$-statistic, and corresponding (two-sided) $p$-value.
vcThe estimated variance-covariance matrix of the MLEs
betaThe MLEs from the count component of the model
gammaThe MLEs from the zero-inflated component of the model
thetaIf a zero-inflated negative binomial model is fit, the MLE of the over-dispersion parameter
llhThe value of the log-likelihood function at the MLEs

Details

print.summary.zeroinfl tries to be smart about formatting the display of the MLEs, standard errors, etc, essentially using the same code as appears in link{print.summary.lm}

Examples

Run this code

data(bioChemists)
zip <- zeroinfl(count=art ~ .,
                x = ~ fem + mar + kid5 + phd + ment,
                z = ~ fem + mar + kid5 + phd + ment,
                data=bioChemists,trace=TRUE)
summary(zip)
coef(zip)
logLik(zip)

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