From 6982cc5affe8cec498e6559314c767f6a9475f99 Mon Sep 17 00:00:00 2001
From: gkennedy <graeme.kennedy@ae.gatech.edu>
Date: Tue, 8 Apr 2025 15:59:06 -0400
Subject: [PATCH] added log function for adscalar

---
 include/adscalar.h | 11 +++++++++++
 1 file changed, 11 insertions(+)

diff --git a/include/adscalar.h b/include/adscalar.h
index 673f144..e8bcfb3 100644
--- a/include/adscalar.h
+++ b/include/adscalar.h
@@ -349,6 +349,17 @@ A2D_FUNCTION inline ADScalar<X, M> exp(const ADScalar<X, M> &r) {
   return out;
 }
 
+template <class X, int M>
+A2D_FUNCTION inline ADScalar<X, M> log(const ADScalar<X, M> &r) {
+  // device compatible log
+  ADScalar<X, M> out(::log(r.value));
+  X inv = 1.0 / r.value;
+  for (int i = 0; i < M; i++) {
+    out.deriv[i] = inv * r.deriv[i];
+  }
+  return out;
+}
+
 template <class X, int M>
 A2D_FUNCTION inline ADScalar<X, M> sin(const ADScalar<X, M> &r) {
   // device compatible sin, cos