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

Stan code for the zero-inflated negative-binomial log probability mass function.

Examples

cat(zi_neg_binomial_2_lpmf_stan[["source_code"]])
#> real zi_neg_binomial_2_lpmf(int n, real mu, real phi, real pi) {
#> 
#>   if (pi < 0 || pi > 1) {
#>     reject("pi should be in [0, 1]; pi=", pi);
#>   }
#> 
#>     // 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)));
#> }