Zero-inflated Poisson Linked Log Probability Mass Function Stan Code

Stan code for the zero-inflated Poisson distribution's log probability mass function, where the amount of zero-inflation is a function of the mean.

Examples

cat(zi_poisson_linked_lpmf_stan[["source_code"]])
#> real zi_poisson_linked_lpmf(int n, real lambda, real gamma0, real gamma1) {
#> 
#>   real pi = inv_logit(gamma0 + gamma1 * lambda);
#> 
#>   // TODO: Would this be more efficient if it used log_sum_exp?
#>   return log(pi * (n == 0) + (1 - pi) * exp(poisson_lpmf(n | lambda)));
#> }