use sigmoid function instead of tanh

goml · May 13, 2014 · 8681fc7 · 8681fc7
1 parent 1d18786
commit 8681fc7
Showing 1 changed file with 2 additions and 2 deletions.
diff --git a/neuralnetwork/neuralnetwork.go b/neuralnetwork/neuralnetwork.go
@@ -27,11 +27,11 @@ func vector(I int, fill float64) []float64 {
 }
 
 func sigmoid(x float64) float64 {
-	return math.Tanh(x)
+	return 1 / (1 + math.Exp(-x))
 }
 
 func dsigmoid(y float64) float64 {
-	return 1.0 - y*y
+	return y * (1 - y)
 }
 
 type NeuralNetwork struct {