Re-use computation

andrjohns · andrjohns · commit f627b3750f4d · 2024-03-26T17:12:37.000+02:00
diff --git a/stan/math/prim/prob/weibull_cdf.hpp b/stan/math/prim/prob/weibull_cdf.hpp
@@ -69,8 +69,8 @@ return_type_t<T_y, T_shape, T_scale> weibull_cdf(const T_y& y,
   constexpr bool any_derivs = !is_constant_all<T_y, T_shape, T_scale>::value;
   const auto& log_y = to_ref_if<any_derivs>(log(y_val));
   const auto& log_sigma = to_ref_if<any_derivs>(log(sigma_val));
-  const auto& log_pow_n
-      = to_ref_if<any_derivs>(alpha_val * log_y - alpha_val * log_sigma);
+  const auto& log_y_div_sigma = to_ref_if<any_derivs>(log_y - log_sigma);
+  const auto& log_pow_n = to_ref_if<any_derivs>(alpha_val * log_y_div_sigma);
   const auto& pow_n = to_ref_if<any_derivs>(exp(log_pow_n));
   const auto& log_cdf_n = to_ref_if<any_derivs>(log1m_exp(-pow_n));
 
@@ -88,7 +88,7 @@ return_type_t<T_y, T_shape, T_scale> weibull_cdf(const T_y& y,
       }
     }
     if (!is_constant_all<T_shape>::value) {
-      partials<1>(ops_partials) = exp(log_rep_deriv) * (log_y - log_sigma);
+      partials<1>(ops_partials) = exp(log_rep_deriv) * log_y_div_sigma;
     }
   }
   return ops_partials.build(exp(log_cdf));
diff --git a/stan/math/prim/prob/weibull_lcdf.hpp b/stan/math/prim/prob/weibull_lcdf.hpp
@@ -68,8 +68,8 @@ return_type_t<T_y, T_shape, T_scale> weibull_lcdf(const T_y& y,
   constexpr bool any_derivs = !is_constant_all<T_y, T_shape, T_scale>::value;
   const auto& log_y = to_ref_if<any_derivs>(log(y_val));
   const auto& log_sigma = to_ref_if<any_derivs>(log(sigma_val));
-  const auto& log_pow_n
-      = to_ref_if<any_derivs>(alpha_val * log_y - alpha_val * log_sigma);
+  const auto& log_y_div_sigma = to_ref_if<any_derivs>(log_y - log_sigma);
+  const auto& log_pow_n = to_ref_if<any_derivs>(alpha_val * log_y_div_sigma);
   const auto& pow_n = to_ref_if<any_derivs>(exp(log_pow_n));
 
   if (any_derivs) {
@@ -85,7 +85,7 @@ return_type_t<T_y, T_shape, T_scale> weibull_lcdf(const T_y& y,
       }
     }
     if (!is_constant_all<T_shape>::value) {
-      partials<1>(ops_partials) = exp(log_rep_deriv) * (log_y - log_sigma);
+      partials<1>(ops_partials) = exp(log_rep_deriv) * log_y_div_sigma;
     }
   }
   return ops_partials.build(sum(log1m_exp(-pow_n)));

Original file line number	Diff line number	Diff line change
`@@ -69,8 +69,8 @@ return_type_t<T_y, T_shape, T_scale> weibull_cdf(const T_y& y,`
`69`	`69`	`constexpr bool any_derivs = !is_constant_all<T_y, T_shape, T_scale>::value;`
`70`	`70`	`const auto& log_y = to_ref_if<any_derivs>(log(y_val));`
`71`	`71`	`const auto& log_sigma = to_ref_if<any_derivs>(log(sigma_val));`
`72`		`- const auto& log_pow_n`
`73`		`- = to_ref_if<any_derivs>(alpha_val * log_y - alpha_val * log_sigma);`
	`72`	`+ const auto& log_y_div_sigma = to_ref_if<any_derivs>(log_y - log_sigma);`
	`73`	`+ const auto& log_pow_n = to_ref_if<any_derivs>(alpha_val * log_y_div_sigma);`
`74`	`74`	`const auto& pow_n = to_ref_if<any_derivs>(exp(log_pow_n));`
`75`	`75`	`const auto& log_cdf_n = to_ref_if<any_derivs>(log1m_exp(-pow_n));`
`76`	`76`
`@@ -88,7 +88,7 @@ return_type_t<T_y, T_shape, T_scale> weibull_cdf(const T_y& y,`
`88`	`88`	`}`
`89`	`89`	`}`
`90`	`90`	`if (!is_constant_all<T_shape>::value) {`
`91`		`- partials<1>(ops_partials) = exp(log_rep_deriv) * (log_y - log_sigma);`
	`91`	`+ partials<1>(ops_partials) = exp(log_rep_deriv) * log_y_div_sigma;`
`92`	`92`	`}`
`93`	`93`	`}`
`94`	`94`	`return ops_partials.build(exp(log_cdf));`
Original file line number	Diff line number	Diff line change
`@@ -68,8 +68,8 @@ return_type_t<T_y, T_shape, T_scale> weibull_lcdf(const T_y& y,`
`68`	`68`	`constexpr bool any_derivs = !is_constant_all<T_y, T_shape, T_scale>::value;`
`69`	`69`	`const auto& log_y = to_ref_if<any_derivs>(log(y_val));`
`70`	`70`	`const auto& log_sigma = to_ref_if<any_derivs>(log(sigma_val));`
`71`		`- const auto& log_pow_n`
`72`		`- = to_ref_if<any_derivs>(alpha_val * log_y - alpha_val * log_sigma);`
	`71`	`+ const auto& log_y_div_sigma = to_ref_if<any_derivs>(log_y - log_sigma);`
	`72`	`+ const auto& log_pow_n = to_ref_if<any_derivs>(alpha_val * log_y_div_sigma);`
`73`	`73`	`const auto& pow_n = to_ref_if<any_derivs>(exp(log_pow_n));`
`74`	`74`
`75`	`75`	`if (any_derivs) {`
`@@ -85,7 +85,7 @@ return_type_t<T_y, T_shape, T_scale> weibull_lcdf(const T_y& y,`
`85`	`85`	`}`
`86`	`86`	`}`
`87`	`87`	`if (!is_constant_all<T_shape>::value) {`
`88`		`- partials<1>(ops_partials) = exp(log_rep_deriv) * (log_y - log_sigma);`
	`88`	`+ partials<1>(ops_partials) = exp(log_rep_deriv) * log_y_div_sigma;`
`89`	`89`	`}`
`90`	`90`	`}`
`91`	`91`	`return ops_partials.build(sum(log1m_exp(-pow_n)));`