f*ck jsperf's crappy sigmoid implementation

1 files changed, 2 insertions, 1 deletions

diff --git a/code/weightvis.js b/code/weightvis.js
index e3cec42..f61ec39 100644
--- a/code/weightvis.js
+++ b/code/weightvis.js
@@ -504,7 +504,7 @@ var NetVisualizer = (function() {
 
     NetVisualizer.prototype.activate = function(inputs) {
         // assumes the sigmoid function is used as activation
-        function activation(x) { return 0.5 + x / Math.sqrt(1 + 4 * x * x); }
+        function activation(x) { return 1 / (1 + Math.exp(-x)); }
         var weights = this.data[this.layout.data.batches-1][this.layout.data.epochs-1];
         var lastLayerOut = inputs;
         var hasBias = false;
@@ -525,6 +525,7 @@ var NetVisualizer = (function() {
                 thisLayerOut[tar] = activation(thisLayerOut[tar]);
             }
             lastLayerOut = thisLayerOut;
+            //console.log("layer out", layer, lastLayerOut);
         }
         return lastLayerOut;
     };