From b32a287e38f4c6a41828f18b4669dec9f3af4943 Mon Sep 17 00:00:00 2001
From: Joseph Redmon <pjreddie@gmail.com>
Date: Thu, 17 Jul 2014 17:17:52 +0000
Subject: [PATCH] Merge branch 'master' of pjreddie.com:jnet
---
src/activations.c | 97 +++++++++++++++++++++++++++++++++++++++++++++---
1 files changed, 90 insertions(+), 7 deletions(-)
diff --git a/src/activations.c b/src/activations.c
index b8bb79d..3b11716 100644
--- a/src/activations.c
+++ b/src/activations.c
@@ -2,8 +2,28 @@
#include <math.h>
#include <stdio.h>
+#include <stdlib.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;
@@ -15,22 +35,40 @@
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, float dropout)
+{
+ if(dropout && (float)rand()/RAND_MAX < dropout) return 0;
switch(a){
case LINEAR:
- return x;
+ return linear_activate(x)/(1-dropout);
case SIGMOID:
- return 1./(1.+exp(-x));
+ return sigmoid_activate(x)/(1-dropout);
case RELU:
- return x*(x>0);
+ return relu_activate(x)/(1-dropout);
case RAMP:
- return x*(x>0) + .1*x;
+ return ramp_activate(x)/(1-dropout);
case TANH:
- return (exp(2*x)-1)/(exp(2*x)+1);
+ return tanh_activate(x)/(1-dropout);
}
return 0;
}
-double gradient(double x, ACTIVATION a){
+
+void activate_array(float *x, const int n, const ACTIVATION a, float dropout)
+{
+ int i;
+ for(i = 0; i < n; ++i){
+ x[i] = activate(x[i], a, dropout);
+ }
+}
+
+
+float gradient(float x, ACTIVATION a){
switch(a){
case LINEAR:
return 1;
@@ -46,3 +84,48 @@
return 0;
}
+void gradient_array(const float *x, const int n, const ACTIVATION a, float *delta)
+{
+ int i;
+ for(i = 0; i < n; ++i){
+ delta[i] *= gradient(x[i], a);
+ }
+}
+
+#ifdef GPU
+
+#include "opencl.h"
+#include <math.h>
+
+cl_kernel get_activation_kernel()
+{
+ static int init = 0;
+ static cl_kernel kernel;
+ if(!init){
+ kernel = get_kernel("src/activations.cl", "activate_array", 0);
+ init = 1;
+ }
+ return kernel;
+}
+
+
+void activate_array_ongpu(cl_mem x, int n, ACTIVATION a, float dropout)
+{
+ cl_setup();
+ cl_kernel kernel = get_activation_kernel();
+ cl_command_queue queue = cl.queue;
+
+ cl_uint i = 0;
+ cl.error = clSetKernelArg(kernel, i++, sizeof(x), (void*) &x);
+ cl.error = clSetKernelArg(kernel, i++, sizeof(n), (void*) &n);
+ cl.error = clSetKernelArg(kernel, i++, sizeof(a), (void*) &a);
+ cl.error = clSetKernelArg(kernel, i++, sizeof(dropout),
+ (void*) &dropout);
+ check_error(cl);
+
+ size_t gsize = n;
+
+ clEnqueueNDRangeKernel(queue, kernel, 1, 0, &gsize, 0, 0, 0, 0);
+ check_error(cl);
+}
+#endif
--
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