python 遗传算法优化bp神经网络_利用遗传算法优化BP神经网络出现了一些问题,求大神解答...
本帖最后由 初学者er 于 2019-3-1 20:25 编辑总是出现错误:错误使用 network/subsasgn>network_subsasgn (line 550)net.IW{1,1} must be a 6-by-0 matrix.出错 network/subsasgn (line 10)net = network_subsasgn(net,subscripts,v,netna
本帖最后由 初学者er 于 2019-3-1 20:25 编辑
总是出现错误:错误使用 network/subsasgn>network_subsasgn (line 550)net.IW{1,1} must be a 6-by-0 matrix.
出错 network/subsasgn (line 10)
net = network_subsasgn(net,subscripts,v,netname);
出错 fun (line 23)
net.iw{1,1}=reshape(w1,hiddennum,inputnum);
出错 gentic (line 33)
individuals.fitness(i)=fun(x,inputnum,hiddennum,outputnum,net,inputn,outputn); %染色体的适应度
改了好多遍都还是有错误,不知道该怎么解决请大神指教啊~
原代码如下:
tic
clear;
clc;
data=xlsread('预测数据.xlsx');
inputnum=24;
hiddennum=6;
outputnum=12;
input_train=data(1:24);
input_test=data(37:60);
output_train=(25:36);
output_test=(61:72);
[inputn,inputps]=mapminmax(input_train);
[outputn,outputps]=mapminmax(output_train);
net=newff(inputn,outputn,hiddennum,{'tansig','purelin'}); %%{'tansig','purelin'}为默认的激活函数(没记错的话,有兴趣的话可以试着进行调整)
%% 遗传算法参数初始化
maxgen=10; %进化代数,即迭代次数
sizepop=30; %种群规模
pcross=0.3; %交叉概率选择,0和1之间
pmutation=0.1; %变异概率选择,0和1之间
numsum=inputnum*hiddennum+hiddennum+hiddennum*outputnum+outputnum;
lenchrom=ones(1,numsum);
bound=[-3*ones(numsum,1) 3*ones(numsum,1)]; %数据范围
individuals=struct('fitness',zeros(1,sizepop), 'chrom',[]); %将种群信息定义为一个结构体
avgfitness=[]; %每一代种群的平均适应度
bestfitness=[]; %每一代种群的最佳适应度
bestchrom=[]; %适应度最好的染色体
for i=1:sizepop %随机产生一个种群
individuals.chrom(i,:)=Code(lenchrom,bound); %编码
x=individuals.chrom(i,:); %计算适应度
individuals.fitness(i)=fun(x,inputnum,hiddennum,outputnum,net,inputn,outputn); %染色体的适应度
end
[bestfitness bestindex]=min(individuals.fitness);
bestchrom=individuals.chrom(bestindex,:); %最好的染色体
avgfitness=sum(individuals.fitness)/sizepop; %染色体的平均适应度
trace=[avgfitness bestfitness]; % 记录每一代进化中最好的适应度和平均适应度
for num=1:maxgen
% 选择
individuals=select(individuals,sizepop);
avgfitness=sum(individuals.fitness)/sizepop;
%交叉
individuals.chrom=Cross(pcross,lenchrom,individuals,sizepop,bound);
% 变异
individuals.chrom=Mutation(pmutation,lenchrom,individuals,sizepop,num,maxgen,bound);
% 计算适应度
for j=1:sizepop
x=individuals.chrom(j,:); %个体
individuals.fitness(j)=fun(x,inputnum,hiddennum,outputnum,net,inputn,outputn);
end
%找到最小和最大适应度的染色体及它们在种群中的位置
[newbestfitness,newbestindex]=min(individuals.fitness);
[worestfitness,worestindex]=max(individuals.fitness);
% 代替上一次进化中最好的染色体
if bestfitness>newbestfitness
bestfitness=newbestfitness;
bestchrom=individuals.chrom(newbestindex,:);
end
individuals.chrom(worestindex,:)=bestchrom;
individuals.fitness(worestindex)=bestfitness;
avgfitness=sum(individuals.fitness)/sizepop;
trace=[trace;avgfitness bestfitness]; %记录每一代进化中最好的适应度和平均适应度
end
figure(1)
[r c]=size(trace);
plot([1:r]',trace(:,2),'b--');
title(['适应度曲线 ' '终止代数=' num2str(maxgen)]);
xlabel('进化代数');ylabel('适应度');
legend('平均适应度','最佳适应度');
disp('适应度 变量');
%% 把最优初始阀值权值赋予网络预测
% %用遗传算法优化的BP网络进行值预测
x=bestchrom;
w1=x(1:inputnum*hiddennum);
B1=x(inputnum*hiddennum+1:inputnum*hiddennum+hiddennum);
w2=x(inputnum*hiddennum+hiddennum+1:inputnum*hiddennum+hiddennum+hiddennum*outputnum);
B2=x(inputnum*hiddennum+hiddennum+hiddennum*outputnum+1:inputnum*hiddennum+hiddennum+hiddennum*outputnum+outputnum);
net.iw{1,1}=reshape(w1,hiddennum,inputnum);
net.lw{2,1}=reshape(w2,outputnum,hiddennum);
net.b{1}=reshape(B1,hiddennum,1);
net.b{2}=reshape(B2,outputnum,1);
%% BP网络训练
%网络参数
net.trainParam.epochs=100;
net.trainParam.lr=0.1;
%net.trainParam.goal=0.00001;
%网络训练
[net,per2]=train(net,inputn,outputn);
%% BP网络预测
%数据归一化
inputn_test=mapminmax('apply',input_test,inputps);
an=sim(net,inputn_test);
test_simu=mapminmax('reverse',an,outputps);
error=test_simu-output_test;
figure(2)
plot(test_simu,':og','LineWidth',1.5)
hold on
plot(output_test,'-*','LineWidth',1.5);
legend('预测输出','期望输出')
grid on
set(gca,'linewidth',1.0);
xlabel('X 样本','FontSize',15);
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
ylabel('Y 输出','FontSize',15);
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
set(gcf,'color','w')
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
title('GA-BP Network','Color','k','FontSize',15);
toc
function error = fun(x,inputnum,hiddennum,outputnum,net,inputn,outputn)
%该函数用来计算适应度值
%x input 个体
%inputnum input 输入层节点数
%outputnum input 隐含层节点数
%net input 网络
%inputn input 训练输入数据
%outputn input 训练输出数据
%error output 个体适应度值
%提取
w1=x(1:inputnum*hiddennum);
B1=x(inputnum*hiddennum+1:inputnum*hiddennum+hiddennum);
w2=x(inputnum*hiddennum+hiddennum+1:inputnum*hiddennum+hiddennum+hiddennum*outputnum);
B2=x(inputnum*hiddennum+hiddennum+hiddennum*outputnum+1:inputnum*hiddennum+hiddennum+hiddennum*outputnum+outputnum);
net=newff(inputn,outputn,hiddennum);
%网络进化参数
net.trainParam.epochs=20;
net.trainParam.lr=0.1;
net.trainParam.goal=0.00001;
net.trainParam.show=100;
net.trainParam.showWindow=0;
%网络权值赋值
net.iw{1,1}=reshape(w1,hiddennum,inputnum);
net.lw{2,1}=reshape(w2,outputnum,hiddennum);
net.b{1}=reshape(B1,hiddennum,1);
net.b{2}=reshape(B2,outputnum,1);
%网络训练
net=train(net,inputn,outputn);
an=sim(net,inputn);
error=sum(abs(an-outputn));
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