From 0f645836f193e75c4c3b718369e6fab15b5d19c5 Mon Sep 17 00:00:00 2001
From: Joseph Redmon <pjreddie@gmail.com>
Date: Wed, 11 Feb 2015 03:41:03 +0000
Subject: [PATCH] Detection is back, baby\!

---
 src/activations.c |   25 +++++++++++++++++--------
 1 files changed, 17 insertions(+), 8 deletions(-)

diff --git a/src/activations.c b/src/activations.c
index 24868a3..48dce87 100644
--- a/src/activations.c
+++ b/src/activations.c
@@ -2,6 +2,7 @@
 
 #include <math.h>
 #include <stdio.h>
+#include <stdlib.h>
 #include <string.h>
 
 char *get_activation_string(ACTIVATION a)
@@ -39,8 +40,16 @@
 float relu_activate(float x){return x*(x>0);}
 float ramp_activate(float x){return x*(x>0)+.1*x;}
 float tanh_activate(float x){return (exp(2*x)-1)/(exp(2*x)+1);}
+//float tanh_activate(float x){return x - (x*x*x)/3;}
 
-float activate(float x, ACTIVATION a){
+float linear_gradient(float x){return 1;}
+float sigmoid_gradient(float x){return (1-x)*x;}
+float relu_gradient(float x){return (x>0);}
+float ramp_gradient(float x){return (x>0)+.1;}
+float tanh_gradient(float x){return 1-x*x;}
+
+float activate(float x, ACTIVATION a)
+{
     switch(a){
         case LINEAR:
             return linear_activate(x);
@@ -64,19 +73,19 @@
     }
 }
 
-
-float gradient(float x, ACTIVATION a){
+float gradient(float x, ACTIVATION a)
+{
     switch(a){
         case LINEAR:
-            return 1;
+            return linear_gradient(x);
         case SIGMOID:
-            return (1.-x)*x;
+            return sigmoid_gradient(x);
         case RELU:
-            return (x>0);
+            return relu_gradient(x);
         case RAMP:
-            return (x>0) + .1;
+            return ramp_gradient(x);
         case TANH:
-            return 1-x*x;
+            return tanh_gradient(x);
     }
     return 0;
 }

--
Gitblit v1.10.0