From 5ef74c2031a040f30a670dc7d60790fc6a9ec720 Mon Sep 17 00:00:00 2001
From: Joseph Redmon <pjreddie@gmail.com>
Date: Fri, 02 May 2014 22:20:34 +0000
Subject: [PATCH] Slowly refactoring and pushing to GPU
---
src/activations.c | 90 +++++++++++++++++++++++++++-----------------
1 files changed, 55 insertions(+), 35 deletions(-)
diff --git a/src/activations.c b/src/activations.c
index a255f0f..24868a3 100644
--- a/src/activations.c
+++ b/src/activations.c
@@ -4,32 +4,70 @@
#include <stdio.h>
#include <string.h>
+char *get_activation_string(ACTIVATION a)
+{
+ switch(a){
+ case SIGMOID:
+ return "sigmoid";
+ case RELU:
+ return "relu";
+ case RAMP:
+ return "ramp";
+ case LINEAR:
+ return "linear";
+ case TANH:
+ return "tanh";
+ default:
+ break;
+ }
+ return "relu";
+}
+
ACTIVATION get_activation(char *s)
{
if (strcmp(s, "sigmoid")==0) return SIGMOID;
if (strcmp(s, "relu")==0) return RELU;
- if (strcmp(s, "identity")==0) return IDENTITY;
+ if (strcmp(s, "linear")==0) return LINEAR;
if (strcmp(s, "ramp")==0) return RAMP;
+ if (strcmp(s, "tanh")==0) return TANH;
fprintf(stderr, "Couldn't find activation function %s, going with ReLU\n", s);
return RELU;
}
-double activate(double x, ACTIVATION a){
+float linear_activate(float x){return x;}
+float sigmoid_activate(float x){return 1./(1. + exp(-x));}
+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 activate(float x, ACTIVATION a){
switch(a){
- case IDENTITY:
- return x;
+ case LINEAR:
+ return linear_activate(x);
case SIGMOID:
- return 1./(1.+exp(-x));
+ return sigmoid_activate(x);
case RELU:
- return x*(x>0);
+ return relu_activate(x);
case RAMP:
- return x*(x>0) + .1*x;
+ return ramp_activate(x);
+ case TANH:
+ return tanh_activate(x);
}
return 0;
}
-double gradient(double x, ACTIVATION a){
+
+void activate_array(float *x, const int n, const ACTIVATION a)
+{
+ int i;
+ for(i = 0; i < n; ++i){
+ x[i] = activate(x[i], a);
+ }
+}
+
+
+float gradient(float x, ACTIVATION a){
switch(a){
- case IDENTITY:
+ case LINEAR:
return 1;
case SIGMOID:
return (1.-x)*x;
@@ -37,35 +75,17 @@
return (x>0);
case RAMP:
return (x>0) + .1;
+ case TANH:
+ return 1-x*x;
}
return 0;
}
-double identity_activation(double x)
+void gradient_array(const float *x, const int n, const ACTIVATION a, float *delta)
{
- return x;
-}
-double identity_gradient(double x)
-{
- return 1;
-}
-
-double relu_activation(double x)
-{
- return x*(x>0);
-}
-double relu_gradient(double x)
-{
- return (x>0);
-}
-
-double sigmoid_activation(double x)
-{
- return 1./(1.+exp(-x));
-}
-
-double sigmoid_gradient(double x)
-{
- return x*(1.-x);
-}
+ int i;
+ for(i = 0; i < n; ++i){
+ delta[i] *= gradient(x[i], a);
+ }
+}
--
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