The COMPoissonReg R package fits COM-Poisson regression (Sellers & Shmueli, 2010) and zero-inflated (ZI) COM-Poisson regression models (Sellers & Raim, 2016). The syntax to fit a model looks like
cmp.out <- glm.cmp(formula.lambda = y ~ x1 + x2, formula.nu = ~ x1, formula.p = ~ x2)
where formula.lambda
is a regression model for the COM-Poisson rate parameter, formula.nu
is a model for the dispersion parameter, and formula.p
is a model for the zero-inflation parameter. See the package documentation for details.