change prob_deriv *= prob

stan-dev · Oct 10, 2024 · 97ab7a9 · 97ab7a9
1 parent 6c8688f
commit 97ab7a9
Showing 1 changed file with 3 additions and 3 deletions.
diff --git a/stan/math/prim/prob/wiener4_lcdf.hpp b/stan/math/prim/prob/wiener4_lcdf.hpp
@@ -338,7 +338,7 @@ inline auto wiener4_cdf_grad_a(const T_y& y, const T_a& a, const T_v& vn,
     const auto pia2 = 2 * pi() / square(a);
     auto prob_deriv
         = ((fabs(v) == 0) ? 0 : is_inf(dav * v) ? NEGATIVE_INFTY : dav * v);
-    prob_deriv *= prob;
+    prob_deriv = prob_deriv * prob;
     ans = (-2 / a - v * w) * (cdf - prob) + ans * pia2 * evaw;
     return prob_deriv + ans;
   }
@@ -450,7 +450,7 @@ inline auto wiener4_cdf_grad_v(const T_y& y, const T_a& a, const T_v& vn,
     const auto dav = log_probability_GradAV(a, v, w);
     const auto pia2 = 2 * pi() / square(a);
     auto prob_deriv = is_inf(dav * a) ? NEGATIVE_INFTY : dav * a;
-    prob_deriv *= prob;
+    prob_deriv = prob_deriv * prob;
     ans = (-w * a - v * y) * (cdf - prob) + ans * (-2 * v) * pia2 * evaw;
     return -1 * (prob_deriv + ans);
   }
@@ -585,7 +585,7 @@ inline auto wiener4_cdf_grad_w(const T_y& y, const T_a& a, const T_v& vn,
 
     const auto pia2 = 2 * pi() / square(a);
     auto prob_deriv = dav;
-    prob_deriv *= prob;
+    prob_deriv = prob_deriv * prob;
     ans = -v * a * (cdf - prob) + ans * pia2 * evaw;
     return -1 * (prob_deriv + ans);
   }