ga.m

MATLAB编写的BP神经网络程序

clc
clear

m=20;
epoch=300;
pc=0.4;
pb=0.01;

for i=1:m
    ind(i)=-1+3*rand;
end

for j=1:epoch
    for p=1:m
        fit(p)=y(ind(p));
    end
    fit_sum=sum(fit);
    for p=1:m
        fit_p(p)=fit(p)/fit_sum;
    end
    K(1)=0;
    for i=1:m
        K(i+1)=K(i)+fit_p(i);
    end
    for p=1:m
        k=rand;
        for q=1:m
            if k>K(q) || k<=K(q+1)
                ind_sel(p)=ind(p);
            end
        end
    end
    
    for i=1:m
        if pc>rand
            rand_num1=round(1+19*rand);
            rand_num2=round(1+19*rand);
            ind_cross(i)=ind_sel(rand_num1)+ind_sel(rand_num2);
        elseif 
            ind_cross(i)=ind_sel(i);
        end
        if pb>rand
            ind_cross(i)=ind_cross(i)+0.2*(-1*3*rand);
            while (ind_cross(i)>2 || ind_cross(i)<-1)
                ind_cross(i)=ind_cross(i)+0.2*(-1*3*rand);
            end
        end
    end
    ind=ind_cross;
end