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Create a zero-inflated Poisson specification

Source: R/zi.R
zi_poisson.Rd

Create a zero-inflated Poisson specification

Usage

zi_poisson(formula = NULL)

Arguments

formula

Optional formula for the zero-inflation probability. If NULL, uses intercept-only model for P(structural zero).

Value

A ratiod_zi object

Examples

# Intercept-only ZI
zi_poisson()
#> tulpaRatio Zero-Inflation Specification
#> ==================================
#> Type: Zero-Inflated Poisson 
#> Formula: ~ 1 (intercept only)

# ZI probability depends on a covariate
zi_poisson(~ habitat)
#> tulpaRatio Zero-Inflation Specification
#> ==================================
#> Type: Zero-Inflated Poisson 
#> Formula: ~habitat