/*
******************************************************************
* backprop.cpp
******************************************************************
*/
#include "StdAfx.h"
#include <stdio.h>
#include "backprop.h"
#include <math.h>
#include <stdlib.h>
#define ABS(x) (((x) > 0.0) ? (x) : (-(x)))
/* 宏定义：快速拷贝 */
#define fastcopy(to,from,len)\
{\
register char *_to,*_from;\
register int _i,_l;\
_to = (char *)(to);\
_from = (char *)(from);\
_l = (len);\
for (_i = 0; _i < _l; _i++) *_to++ = *_from++;\
}
/*** 返回0－1的双精度随机数 ***/
double drnd()
{
return ((double) rand() / (double) BIGRND);
}
/*** 返回-1.0到1.0之间的双精度随机数 ***/
double dpn1()
{
return ((drnd() * 2.0) - 1.0);
}
/*** 作用函数，目前是S型函数 ***/
double squash(double x)
{
return (1.0 / (1.0 + exp(-x)));
}
/*** 申请1维双精度实数数组 ***/
double *alloc_1d_dbl(int n)
{
double *new1;
new1 = (double *) malloc ((unsigned) (n * sizeof (double)));
if (new1 == NULL) {
printf("ALLOC_1D_DBL: Couldn't allocate array of doubles\n");
return (NULL);
}
return (new1);
}
/*** 申请2维双精度实数数组 ***/
double **alloc_2d_dbl(int m, int n)
{
int i;
double **new1;
new1 = (double **) malloc ((unsigned) (m * sizeof (double *)));
if (new1 == NULL) {
printf("ALLOC_2D_DBL: Couldn't allocate array of dbl ptrs\n");
return (NULL);
}
for (i = 0; i < m; i++) {
new1[i] = alloc_1d_dbl(n);
}
return (new1);
}
/*** 随机初始化权值 ***/
void bpnn_randomize_weights(double **w, int m, int n)
{
int i, j;
for (i = 0; i <= m; i++) {
for (j = 0; j <= n; j++) {
w[i][j] = dpn1();
}
}
}
/*** 0初始化权值 ***/
void bpnn_zero_weights(double **w, int m, int n)
{
int i, j;
for (i = 0; i <= m; i++) {
for (j = 0; j <= n; j++) {
w[i][j] = 0.0;
}
}
}
/*** 设置随机数种子 ***/
void bpnn_initialize(int seed)
{
printf("Random number generator seed: %d\n", seed);
srand(seed);
}
/*** 创建BP网络 ***/
BPNN *bpnn_internal_create(int n_in, int n_hidden, int n_out)
{
BPNN *newnet;
newnet = (BPNN *) malloc (sizeof (BPNN));
if (newnet == NULL) {
printf("BPNN_CREATE: Couldn't allocate neural network\n");
return (NULL);
}
newnet->input_n = n_in;
newnet->hidden_n = n_hidden;
newnet->output_n = n_out;
newnet->input_units = alloc_1d_dbl(n_in + 1);
newnet->hidden_units = alloc_1d_dbl(n_hidden + 1);
newnet->output_units = alloc_1d_dbl(n_out + 1);
newnet->hidden_delta = alloc_1d_dbl(n_hidden + 1);
newnet->output_delta = alloc_1d_dbl(n_out + 1);
newnet->target = alloc_1d_dbl(n_out + 1);
newnet->input_weights = alloc_2d_dbl(n_in + 1, n_hidden + 1);
newnet->hidden_weights = alloc_2d_dbl(n_hidden + 1, n_out + 1);
newnet->input_prev_weights = alloc_2d_dbl(n_in + 1, n_hidden + 1);
newnet->hidden_prev_weights = alloc_2d_dbl(n_hidden + 1, n_out + 1);
return (newnet);
}
/* 释放BP网络所占地内存空间 */
void bpnn_free(BPNN *net)
{
int n1, n2, i;
n1 = net->input_n;
n2 = net->hidden_n;
free((char *) net->input_units);
free((char *) net->hidden_units);
free((char *) net->output_units);
free((char *) net->hidden_delta);
free((char *) net->output_delta);
free((char *) net->target);
for (i = 0; i <= n1; i++) {
free((char *) net->input_weights[i]);
free((char *) net->input_prev_weights[i]);
}
free((char *) net->input_weights);
free((char *) net->input_prev_weights);
for (i = 0; i <= n2; i++) {
free((char *) net->hidden_weights[i]);
free((char *) net->hidden_prev_weights[i]);
}
free((char *) net->hidden_weights);
free((char *) net->hidden_prev_weights);
free((char *) net);
}
/***
创建一个BP网络，并初始化权值
***/
BPNN *bpnn_create(int n_in, int n_hidden, int n_out)
{
BPNN *newnet;
newnet = bpnn_internal_create(n_in, n_hidden, n_out);
#ifdef INITZERO
bpnn_zero_weights(newnet->input_weights, n_in, n_hidden);
#else
bpnn_randomize_weights(newnet->input_weights, n_in, n_hidden);
#endif
bpnn_randomize_weights(newnet->hidden_weights, n_hidden, n_out);
bpnn_zero_weights(newnet->input_prev_weights, n_in, n_hidden);
bpnn_zero_weights(newnet->hidden_prev_weights, n_hidden, n_out);
return (newnet);
}
void bpnn_layerforward(double *l1, double *l2, double **conn, int n1, int n2)
{
double sum;
int j, k;
/*** 设置阈值 ***/
l1[0] = 1.0;
/*** 对于第二层的每个神经元 ***/
for (j = 1; j <= n2; j++) {
/*** 计算输入的加权总和 ***/
sum = 0.0;
for (k = 0; k <= n1; k++) {
sum += conn[k][j] * l1[k];
}
l2[j] = squash(sum);
}
}
/* 输出误差 */
void bpnn_output_error(double *delta, double *target, double *output, int nj, double *err)
{
int j;
double o, t, errsum;
errsum = 0.0;
for (j = 1; j <= nj; j++) {
o = output[j];
t = target[j];
delta[j] = o * (1.0 - o) * (t - o);
errsum += ABS(delta[j]);
}
*err = errsum;
}
/* 隐含层误差 */
void bpnn_hidden_error(double* delta_h, int nh, double *delta_o, int no, double **who, double *hidden, double *err)
{
int j, k;
double h, sum, errsum;
errsum = 0.0;
for (j = 1; j <= nh; j++) {
h = hidden[j];
sum = 0.0;
for (k = 1; k <= no; k++) {
sum += delta_o[k] * who[j][k];
}
delta_h[j] = h * (1.0 - h) * sum;
errsum += ABS(delta_h[j]);
}
*err = errsum;
}
/* 调整权值 */
void bpnn_adjust_weights(double *delta, int ndelta, double *ly, int nly, double** w, double **oldw, double eta, double momentum)
{
double new_dw;
int k, j;
ly[0] = 1.0;
for (j = 1; j <= ndelta; j++) {
for (k = 0; k <= nly; k++) {
new_dw = ((eta * delta[j] * ly[k]) + (momentum * oldw[k][j]));
w[k][j] += new_dw;
oldw[k][j] = new_dw;
}
}
}
/* 进行前向运算 */
void bpnn_feedforward(BPNN* net)
{
int in, hid, out;
in = net->input_n;
hid = net->hidden_n;
out = net->output_n;
/*** Feed forward input activations. ***/
bpnn_layerforward(net->input_units, net->hidden_units,
net->input_weights, in, hid);
bpnn_layerforward(net->hidden_units, net->output_units,
net->hidden_weights, hid, out);
}
/* 训练BP网络 */
void bpnn_train(BPNN *net, double eta, double momentum, double *eo, double *eh)
{
int in, hid, out;
double out_err, hid_err;
in = net->input_n;
hid = net->hidden_n;
out = net->output_n;
/*** 前向输入激活 ***/
bpnn_layerforward(net->input_units, net->hidden_units,
net->input_weights, in, hid);
bpnn_layerforward(net->hidden_units, net->output_units,
net->hidden_weights, hid, out);
/*** 计算隐含层和输出层误差 ***/
bpnn_output_error(net->output_delta, net->target, net->output_units,
out, &out_err);
bpnn_hidden_error(net->hidden_delta, hid, net->output_delta, out,
net->hidden_weights, net->hidden_units, &hid_err);
*eo = out_err;
*eh = hid_err;
/*** 调整输入层和隐含层权值 ***/
bpnn_adjust_weights(net->output_delta, out, net->hidden_units, hid,
net->hidden_weights, net->hidden_prev_weights, eta, momentum);
bpnn_adjust_weights(net->hidden_delta, hid, net->input_units, in,
net->input_weights, net->input_prev_weights, eta, momentum);
}
/* 保存BP网络 */
void bpnn_save(BPNN *net, char *filename)
{
int n1, n2, n3, i, j, memcnt;
double dvalue, **w;
char *mem;
FILE *fd;
if ((fd = fopen(filename, "w")) == NULL) {
printf("BPNN_SAVE: Cannot create '%s'\n", filename);
return;
}
n1 = net->input_n; n2 = net->hidden_n; n3 = net->output_n;
printf("Saving %dx%dx%d network to '%s'\n", n1, n2, n3, filename);
fflush(stdout);
fwrite((char *) &n1, sizeof(int), 1, fd);
fwrite((char *) &n2, sizeof(int), 1, fd);
fwrite((char *) &n3, sizeof(int), 1, fd);
memcnt = 0;
w = net->input_weights;
mem = (char *) malloc ((unsigned) ((n1+1) * (n2+1) * sizeof(double)));
for (i = 0; i <= n1; i++) {
for (j = 0; j <= n2; j++) {
dvalue = w[i][j];
fastcopy(&mem[memcnt], &dvalue, sizeof(double));
memcnt += sizeof(double);
}
}
fwrite(mem, (n1+1) * (n2+1) * sizeof(double), 1, fd);
free(mem);
memcnt = 0;
w = net->hidden_weights;
mem = (char *) malloc ((unsigned) ((n2+1) * (n3+1) * sizeof(double)));
for (i = 0; i <= n2; i++) {
for (j = 0; j <= n3; j++) {
dvalue = w[i][j];
fastcopy(&mem[memcnt], &dvalue, sizeof(doub
