Zero-inflated Negative-binomial Log-linked Log Probability Mass Function Stan Code

Stan code for the zero-inflated negative-binomial log probability mass function, where the amount of zero-inflation is a function of log(mean).

Examples

cat(zi_neg_binomial_log_linked_2_lpmf_stan[["source_code"]])
#> real zi_neg_binomial_log_linked_2_lpmf(int n, real mu, real phi, real gamma0, real gamma1) {
#> 
#>   real pi = inv_logit(gamma0 + gamma1 * log(mu));
#> 
#>   // TODO: Would this be more efficient if it used log_sum_exp?
#>   return log(pi * (n == 0) + (1 - pi) * exp(neg_binomial_2_lpmf(n | mu, phi)));
#> }