use prob as default for negative binomial

R/dsl-distributions.R

@@ -125,6 +125,21 @@ distr_hypergeometric <- distribution(
     mean = quote(k * n1 / (n1 + n2))),
   cpp = list(density = "hypergeometric", sample = "hypergeometric"))
 
+distr_negative_binomial_prob <- distribution(
+  name = "NegativeBinomial",
+  variant = "prob",
+  density = function(x, size, prob) {
+    dnbinom(x, size, prob = prob, log = TRUE)
+  },
+  domain = c(0, Inf),
+  sample = function(rng, size, prob) rng$negative_binomial_prob(1, size, prob),
+  expr = list(
+    density = quote(lgamma(x + size) - lgamma(size) - lgamma(x + 1) +
+                      x * log(1 - prob) + size * log(prob)),
+    mean = quote(size * (1 - prob) / prob)),
+  cpp = list(density = "negative_binomial_prob",
+             sample = "negative_binomial_prob"))
+
 distr_negative_binomial_mu <- distribution(
   name = "NegativeBinomial",
   variant = "mu",
@@ -140,20 +155,6 @@ distr_negative_binomial_mu <- distribution(
     mean = quote(mu)),
   cpp = list(density = "negative_binomial_mu", sample = "negative_binomial_mu"))
 
-distr_negative_binomial_prob <- distribution(
-  name = "NegativeBinomial",
-  variant = "prob",
-  density = function(x, size, prob) {
-    dnbinom(x, size, prob = prob, log = TRUE)
-  },
-  domain = c(0, Inf),
-  sample = function(rng, size, prob) rng$negative_binomial_prob(1, size, prob),
-  expr = list(
-    density = quote(lgamma(x + size) - lgamma(size) - lgamma(x + 1) +
-                      x * log(1 - prob) + size * log(prob)),
-    mean = quote(size * (1 - prob) / prob)),
-  cpp = list(density = "negative_binomial_prob", sample = "negative_binomial_prob"))
-
 distr_normal <- distribution(
   name = "Normal",
   density = function(x, mean, sd) dnorm(x, mean, sd, log = TRUE),
@@ -195,8 +196,8 @@ dsl_distributions <- local({
     distr_gamma_rate,
     distr_gamma_scale,
     distr_hypergeometric,
-    distr_negative_binomial_mu,
     distr_negative_binomial_prob,
+    distr_negative_binomial_mu,
     distr_normal,
     distr_poisson,
     distr_uniform)