BP神经网络matlab源程序代码讲解

BP神经网络matlab源程序代码讲解,第1张

newff 创建前向BP网络格式:

net = newff(PR,[S1 S2...SNl],{TF1 TF2...TFNl},BTF,BLF,PF)

其中:PR —— R维输入元粗闹乱素的R×2阶岩档最大最小值矩阵; Si —— 第i层神经元的个数,共N1层; TFi——第i层的转移函数,默认‘tansig’; BTF—— BP网络的训练函数,默认‘trainlm’ BLF—— BP权值/偏差学习函数,默认弯汪’learngdm’ PF ——性能函数,默认‘mse’;(误差

e.g.

P = [0 1 2 3 4 5 6 7 8 9 10]T = [0 1 2 3 4 3 2 1 2 3 4]

net = newff([0 10],[5 1],{'tansig' 'purelin'})net.trainparam.show=50 %每次循环50次net.trainParam.epochs = 500 %最大循环500次

net.trainparam.goal=0.01 %期望目标误差最小值

net = train(net,P,T) %对网络进行反复训练

Y = sim(net,P)Figure % 打开另外一个图形窗口

plot(P,T,P,Y,'o')

load data3_1.txt

[m,n]=size( data3_1)

tsx = data3_1(1:m-1,1)

tsx=tsx'

ts = data3_1(2:m,1)

ts=ts'

[TSX,TSXps]=mapminmax(tsx,1,2)

[TS,TSps]=mapminmax(ts,1,2)

TSX=TSX'

figure

plot(ts,'LineWidth',2)

title('到杭旅游总人数(1999.01.01-2009.12.31)','FontSize',12)

xlabel('统计年份(1990.12.19-2009.08.19)','FontSize',12)

ylabel('归一化后的总游客数/万人','FontSize',12)

grid on

% 生成BP网络、利用minmax函数求输入样本范围

net_1=newff(minmax(TS),[10,1],{'tansig','purelin'},'traincgf')

% 设置训练参数

net_1.trainParam.show = 50 %显示训练迭代过程(NaN表示不显示,缺省25)

net_1.trainParam.lr = 0.025%学习率(缺省埋旅森0.01)

net_1.trainParam.mc = 0.9 %动量因子(缺省0.9)

net_1.trainParam.epochs = 10000%最大训练次数

net_1.trainParam.goal = 0.001 %训练要求镇卖精度

inputWeights=net_1.IW{1,1} %输入层权值

inputbias=net_1.b{1} %输入弯亩层阈值

layerWeights=net_1.LW{2,1} %输出层权值

layerbias=net_1.b{2} %输出层阈值

TS',TSX

% 网络训练

[net_1,tr]=train(net_1,TS,TSX)

// AnnBP.cpp: implementation of the CAnnBP class.

//

///////////////////////////////////////////////////////////////碰枝铅///////

#include "StdAfx.h"

#include "AnnBP.h"

#include "math.h"

/搭扰/////////////////////////////////////////////////////////////////////

// Construction/Destruction

///////////////////////////笑好///////////////////////////////////////////

CAnnBP::CAnnBP()

{

eta1=0.3

momentum1=0.3

}

CAnnBP::~CAnnBP()

{

}

double CAnnBP::drnd()

{

return ((double) rand() / (double) BIGRND)

}

/*** 返回-1.0到1.0之间的双精度随机数 ***/

double CAnnBP::dpn1()

{

return (double) (rand())/(32767/2)-1

}

/*** 作用函数,目前是S型函数 ***/

double CAnnBP::squash(double x)

{

return (1.0 / (1.0 + exp(-x)))

}

/*** 申请1维双精度实数数组 ***/

double* CAnnBP::alloc_1d_dbl(int n)

{

double *new1

new1 = (double *) malloc ((unsigned) (n * sizeof (double)))

if (new1 == NULL) {

AfxMessageBox("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** CAnnBP::alloc_2d_dbl(int m, int n)

{

int i

double **new1

new1 = (double **) malloc ((unsigned) (m * sizeof (double *)))

if (new1 == NULL) {

AfxMessageBox("ALLOC_2D_DBL: Couldn't allocate array of dbl ptrs\n")

return (NULL)

}

for (i = 0i <mi++) {

new1[i] = alloc_1d_dbl(n)

}

return (new1)

}

/*** 随机初始化权值 ***/

void CAnnBP::bpnn_randomize_weights(double **w, int m, int n)

{

int i, j

for (i = 0i <= mi++) {

for (j = 0j <= nj++) {

w[i][j] = dpn1()

}

}

}

/*** 0初始化权值 ***/

void CAnnBP::bpnn_zero_weights(double **w, int m, int n)

{

int i, j

for (i = 0i <= mi++) {

for (j = 0j <= nj++) {

w[i][j] = 0.0

}

}

}

/*** 设置随机数种子 ***/

void CAnnBP::bpnn_initialize(int seed)

{

CString msg,s

msg="Random number generator seed:"

s.Format("%d",seed)

AfxMessageBox(msg+s)

srand(seed)

}

/*** 创建BP网络 ***/

BPNN* CAnnBP::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 CAnnBP::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 = 0i <= n1i++) {

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 = 0i <= n2i++) {

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* CAnnBP::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 CAnnBP::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 = 1j <= n2j++) {

/*** 计算输入的加权总和 ***/

sum = 0.0

for (k = 0k <= n1k++) {

sum += conn[k][j] * l1[k]

}

l2[j] = squash(sum)

}

}

/* 输出误差 */

void CAnnBP::bpnn_output_error(double *delta, double *target, double *output, int nj, double *err)

{

int j

double o, t, errsum

errsum = 0.0

for (j = 1j <= njj++) {

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 CAnnBP::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 = 1j <= nhj++) {

h = hidden[j]

sum = 0.0

for (k = 1k <= nok++) {

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 CAnnBP::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 = 1j <= ndeltaj++) {

for (k = 0k <= nlyk++) {

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 CAnnBP::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 CAnnBP::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 CAnnBP::bpnn_save(BPNN *net, char *filename)

{

CFile file

char *mem

int n1, n2, n3, i, j, memcnt

double dvalue, **w

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)

try

{

file.Open(filename,CFile::modeWrite|CFile::modeCreate|CFile::modeNoTruncate)

}

catch(CFileException* e)

{

e->ReportError()

e->Delete()

}

file.Write(&n1,sizeof(int))

file.Write(&n2,sizeof(int))

file.Write(&n3,sizeof(int))

memcnt = 0

w = net->input_weights

mem = (char *) malloc ((unsigned) ((n1+1) * (n2+1) * sizeof(double)))

// mem = (char *) malloc (((n1+1) * (n2+1) * sizeof(double)))

for (i = 0i <= n1i++) {

for (j = 0j <= n2j++) {

dvalue = w[i][j]

//fastcopy(&mem[memcnt], &dvalue, sizeof(double))

fastcopy(&mem[memcnt], &dvalue, sizeof(double))

memcnt += sizeof(double)

}

}

file.Write(mem,sizeof(double)*(n1+1)*(n2+1))

free(mem)

memcnt = 0

w = net->hidden_weights

mem = (char *) malloc ((unsigned) ((n2+1) * (n3+1) * sizeof(double)))

// mem = (char *) malloc (((n2+1) * (n3+1) * sizeof(double)))

for (i = 0i <= n2i++) {

for (j = 0j <= n3j++) {

dvalue = w[i][j]

fastcopy(&mem[memcnt], &dvalue, sizeof(double))

// fastcopy(&mem[memcnt], &dvalue, sizeof(double))

memcnt += sizeof(double)

}

}

file.Write(mem, (n2+1) * (n3+1) * sizeof(double))

// free(mem)

file.Close()

return

}

/* 从文件中读取BP网络 */

BPNN* CAnnBP::bpnn_read(char *filename)

{

char *mem

BPNN *new1

int n1, n2, n3, i, j, memcnt

CFile file

try

{

file.Open(filename,CFile::modeRead|CFile::modeCreate|CFile::modeNoTruncate)

}

catch(CFileException* e)

{

e->ReportError()

e->Delete()

}

// printf("Reading '%s'\n", filename)// fflush(stdout)

file.Read(&n1, sizeof(int))

file.Read(&n2, sizeof(int))

file.Read(&n3, sizeof(int))

new1 = bpnn_internal_create(n1, n2, n3)

// printf("'%s' contains a %dx%dx%d network\n", filename, n1, n2, n3)

// printf("Reading input weights...")// fflush(stdout)

memcnt = 0

mem = (char *) malloc (((n1+1) * (n2+1) * sizeof(double)))

file.Read(mem, ((n1+1)*(n2+1))*sizeof(double))

for (i = 0i <= n1i++) {

for (j = 0j <= n2j++) {

//fastcopy(&(new1->input_weights[i][j]), &mem[memcnt], sizeof(double))

fastcopy(&(new1->input_weights[i][j]), &mem[memcnt], sizeof(double))

memcnt += sizeof(double)

}

}

free(mem)

// printf("Done\nReading hidden weights...") //fflush(stdout)

memcnt = 0

mem = (char *) malloc (((n2+1) * (n3+1) * sizeof(double)))

file.Read(mem, (n2+1) * (n3+1) * sizeof(double))

for (i = 0i <= n2i++) {

for (j = 0j <= n3j++) {

//fastcopy(&(new1->hidden_weights[i][j]), &mem[memcnt], sizeof(double))

fastcopy(&(new1->hidden_weights[i][j]), &mem[memcnt], sizeof(double))

memcnt += sizeof(double)

}

}

free(mem)

file.Close()

printf("Done\n") //fflush(stdout)

bpnn_zero_weights(new1->input_prev_weights, n1, n2)

bpnn_zero_weights(new1->hidden_prev_weights, n2, n3)

return (new1)

}

void CAnnBP::CreateBP(int n_in, int n_hidden, int n_out)

{

net=bpnn_create(n_in,n_hidden,n_out)

}

void CAnnBP::FreeBP()

{

bpnn_free(net)

}

void CAnnBP::Train(double *input_unit,int input_num, double *target,int target_num, double *eo, double *eh)

{

for(int i=1i<=input_numi++)

{

net->input_units[i]=input_unit[i-1]

}

for(int j=1j<=target_numj++)

{

net->target[j]=target[j-1]

}

bpnn_train(net,eta1,momentum1,eo,eh)

}

void CAnnBP::Identify(double *input_unit,int input_num,double *target,int target_num)

{

for(int i=1i<=input_numi++)

{

net->input_units[i]=input_unit[i-1]

}

bpnn_feedforward(net)

for(int j=1j<=target_numj++)

{

target[j-1]=net->output_units[j]

}

}

void CAnnBP::Save(char *filename)

{

bpnn_save(net,filename)

}

void CAnnBP::Read(char *filename)

{

net=bpnn_read(filename)

}

void CAnnBP::SetBParm(double eta, double momentum)

{

eta1=eta

momentum1=momentum

}

void CAnnBP::Initialize(int seed)

{

bpnn_initialize(seed)

}


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