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Data Summarization

Explore count response variables numerically and graphically before fitting a model.

summarizeCountData()
Summarize count data

Model Fitting

Individual model fitters. Each returns exponentiated coefficients with 95% Wald confidence intervals, randomized quantile residuals, a Pearson dispersion ratio, and a two-panel diagnostic plot.

Poisson

poissonGLM()
Fit a Poisson regression model

Negative Binomial

negbinGLM()
Fit a negative binomial regression model

Zero-Inflated Poisson

zeroinflPoissonGLM()
Fit a zero-inflated Poisson regression model

Zero-Inflated Negative Binomial

zeroinflNegbinGLM()
Fit a zero-inflated negative binomial regression model

Model Selection

Fit all four model families and select the best by AIC, with plain-language diagnostics to guide interpretation.

countGLM()
Fit and compare count regression models