BP网络练习（二）

上次用MATLAB做的，这次尝试用C写了下，有待改进！

#include <stdio.h>#include <math.h>double daoshu(double p)//求导数函数{double d;d = 1/p;return d;}int main(int argc,char argv[]){int n;double P[10] = {4,11,23,34,47,58,62,71,89,97},D[10],OUT[10];//10个样本for(n=0;n<10;n++)//目标结果：D=1/P{D[n] = daoshu(P[n]);}double w11 = 1,w12 = 1,w13 = 1,w21 = 1,w22 = 1,w23 = 1;//初始权值double v11,v12,v13,v2,y1,y2,y3,O;//加权和v，各层输出y,Oint T = 0, epoch = 0;//周期T,输入样本次数epochdouble E = 0,Ee = 0,e = 0;//平均方差E,方差edouble Eta = 0.5,Delta11,Delta12,Delta13,Delta2;//步长Eta，梯度Deltawhile(epoch==0||(0.5*0.1*Ee>0.00001&&T<200))//开始训练；误差较大继续训练，周期较少继续训练{Ee = 0;//误差和归零for(n=0;n<10;n++){//隐层加权求和v11 = w11*P[n];  v12 = w12*P[n];v13 = w13*P[n];//隐层输出y1 = 1/(exp(-v11)+1);y2 = 1/(exp(-v12)+1);y3 = 1/(exp(-v13)+1);//输出层加权求和v2 = w21*y1+w22*y2+w23*y3;//输出层输出O = 1/(exp(-v2)+1);//输出层误差e = D[n]-O;//样本方差累计Ee = Ee+0.5*pow(e,2);//输出层梯度Delta2 = e*O*(1-O);//输出层权值更新w21 = w21+Eta*Delta2*y1;w22 = w22+Eta*Delta2*y2;w23 = w23+Eta*Delta2*y3;//隐层梯度Delta11 = y1*(1-y1)*(Delta2*(w21+w22+w23));Delta12 = y2*(1-y2)*(Delta2*(w21+w22+w23));Delta13 = y3*(1-y3)*(Delta2*(w21+w22+w23));//隐层权值更新w11 = w11+Eta*Delta11*P[n];w12 = w12+Eta*Delta12*P[n];w13 = w13+Eta*Delta13*P[n];//样本输入数加一epoch++;}//周期数加一T++;//平均方差E = 0.5*0.1*Ee;if(T<200)printf("T = %d;E = %f\n",T,E);}//输出训练结果printf("E = %e\n epoch = %d  T = %d\n w11 = %f  w12 = %f  w13 = %f  w21 = %f  w22 = %f  w23 = %f\n\n",E,epoch,T,w11,w12,w13,w21,w22,w23);//仿真样本double Q[10] = {5,10,20,30,40,50,60,70,80,90};for(n=0;n<10;n++){D[n] = daoshu(Q[n]);}printf("Q: ");for(n=0;n<10;n++){printf("%f ",Q[n]);}printf("\n\n");//目标结果printf("D: ");for(n=0;n<10;n++){printf("%f ",D[n]);}printf("\n\n");//仿真for(n=0;n<10;n++){v11 = w11*P[n];  v12 = w12*P[n];y1 = 1/(exp(-v11)+1);y2 = 1/(exp(-v12)+1);v2 = w21*y1+w22*y2;OUT[n] = 1/(exp(-v2)+1);}//仿真结果printf("O: ");for(n=0;n<10;n++){printf("%f ",OUT[n]);}printf("\n");getchar();}