Computes the first-exposure effect (FEE) for a model estimated using the
one-inflated zero-truncated negative binomial distribution. The FEE represents
the change in expected counts associated with the first exposure to treatment,
relative to the counterfactual zero-truncated negative binomial model. This
function is used internally by fee at given covariate values.
fee_negbin(b, g, a, X, Z)A numeric vector of first-exposure effect(s).
A numeric vector of estimated coefficients for the rate.
A numeric vector of estimated coefficients for inflation.
A dispersion parameter from the negative binomial model.
A numeric matrix of covariates for the rate.
A numeric matrix of covariates for inflation.
fee, fee_pois