apply_scalary_binary -> apply_scalar_unary

Author: andrjohns

stan/math/rev/fun/inv_Phi.hpp

@@ -38,10 +38,8 @@ template <typename T, require_var_matrix_t<T>* = nullptr>
 inline auto inv_Phi(const T& p) {
   const auto& arena_rtn = to_arena(inv_Phi(p.val()));
   return make_callback_var(arena_rtn, [p, arena_rtn](auto& vi) mutable {
-    p.adj() += apply_scalar_binary(
-        vi.adj(), arena_rtn.val(), [](const double adj, const double rtn_val) {
-          return adj * exp(-std_normal_lpdf(rtn_val));
-        });
+    auto deriv = arena_rtn.unaryExpr([](auto x) { return exp(-std_normal_lpdf(x)); });
+    p.adj() += elt_multiply(vi.adj(), deriv);
   });
 }
 

stan/math/rev/prob/std_normal_log_qf.hpp

@@ -21,11 +21,14 @@ template <typename T, require_stan_scalar_or_eigen_t<T>* = nullptr>
 inline auto std_normal_log_qf(const var_value<T>& log_p) {
   const auto& arena_rtn = to_arena(std_normal_log_qf(log_p.val()));
   return make_callback_var(arena_rtn, [log_p, arena_rtn](auto& vi) mutable {
-    auto deriv = apply_scalar_binary(
-        log_p.val(), arena_rtn, [](const auto& logp_val, const auto& rtn_val) {
-          return exp(logp_val - std_normal_lpdf(rtn_val));
-        });
-    log_p.adj() += elt_multiply(vi.adj(), deriv);
+    if constexpr (is_eigen<decltype(arena_rtn)>::value) {
+      auto deriv = exp(log_p.val() -  arena_rtn.unaryExpr([](auto x) { 
+        return std_normal_lpdf(x);}));
+      log_p.adj() += elt_multiply(vi.adj(), deriv);
+    } else {
+      auto deriv = exp(log_p.val() -  std_normal_lpdf(arena_rtn));
+      log_p.adj() += vi.adj() * deriv;
+    }
   });
 }