From 00d483697a6e395ef6776320cd1e52a04f4367be Mon Sep 17 00:00:00 2001
From: Joseph Redmon <pjreddie@gmail.com>
Date: Wed, 30 Apr 2014 23:17:40 +0000
Subject: [PATCH] Small updates
---
src/activations.c | 88 ++++++++++++++++++++++++++++++++++----------
1 files changed, 68 insertions(+), 20 deletions(-)
diff --git a/src/activations.c b/src/activations.c
index a128029..24868a3 100644
--- a/src/activations.c
+++ b/src/activations.c
@@ -4,40 +4,88 @@
#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 identity_activation(double x)
-{
- return x;
-}
-double identity_gradient(double x)
-{
- return 1;
+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 LINEAR:
+ return linear_activate(x);
+ case SIGMOID:
+ return sigmoid_activate(x);
+ case RELU:
+ return relu_activate(x);
+ case RAMP:
+ return ramp_activate(x);
+ case TANH:
+ return tanh_activate(x);
+ }
+ return 0;
}
-double relu_activation(double x)
+void activate_array(float *x, const int n, const ACTIVATION a)
{
- return x*(x>0);
-}
-double relu_gradient(double x)
-{
- return (x>=0);
+ int i;
+ for(i = 0; i < n; ++i){
+ x[i] = activate(x[i], a);
+ }
}
-double sigmoid_activation(double x)
-{
- return 1./(1.+exp(-x));
+
+float gradient(float x, ACTIVATION a){
+ switch(a){
+ case LINEAR:
+ return 1;
+ case SIGMOID:
+ return (1.-x)*x;
+ case RELU:
+ return (x>0);
+ case RAMP:
+ return (x>0) + .1;
+ case TANH:
+ return 1-x*x;
+ }
+ return 0;
}
-double sigmoid_gradient(double x)
+void gradient_array(const float *x, const int n, const ACTIVATION a, float *delta)
{
- return x*(1.-x);
-}
+ int i;
+ for(i = 0; i < n; ++i){
+ delta[i] *= gradient(x[i], a);
+ }
+}
--
Gitblit v1.10.0