Merge pull request BVLC#3411 from ghost/patch-3

sigmoid fix: calculate by tanh instead of exp (cpp)
zhwis · Apr 14, 2017 · 6137b24 · 6137b24
2 parents 1df3a25 + 0f61cc0
commit 6137b24
Showing 1 changed file with 1 addition and 1 deletion.
diff --git a/src/caffe/layers/sigmoid_layer.cpp b/src/caffe/layers/sigmoid_layer.cpp
@@ -7,7 +7,7 @@ namespace caffe {
 
 template <typename Dtype>
 inline Dtype sigmoid(Dtype x) {
-  return 1. / (1. + exp(-x));
+  return 0.5 * tanh(0.5 * x) + 0.5;
 }
 
 template <typename Dtype>