PSO：利用PSO+ω参数实现对一元函数y = sin(10*pi*x) ./ x进行求解优化，找到最优个体适应度

Posted 2020-10-25 一个处女座的IT

x = 1:0.01:2;          
y = sin(10*pi*x) ./ x; 
figure
plot(x, y)
title(\'绘制目标函数曲线图—Jason niu\');
hold on


c1 = 1.49445; 
c2 = 1.49445;

maxgen = 50;     
sizepop = 10;   

Vmax = 0.5;    
Vmin = -0.5;
popmax = 2;     
popmin = 1;

ws = 0.9;   
we = 0.4;

for i = 1:sizepop

    pop(i,:) = (rands(1) + 1) / 2 + 1;    
    V(i,:) = 0.5 * rands(1);  

    fitness(i) = fun(pop(i,:));
end


[bestfitness bestindex] = max(fitness); 
zbest = pop(bestindex,:);  
gbest = pop;    
fitnessgbest = fitness;   
fitnesszbest = bestfitness;   

for i = 1:maxgen
    w = ws - (ws-we)*(i/maxgen);   
    for j = 1:sizepop

        V(j,:) = w*V(j,:) + c1*rand*(gbest(j,:) - pop(j,:)) + c2*rand*(zbest - pop(j,:)); 
        V(j,find(V(j,:)>Vmax)) = Vmax;  
        V(j,find(V(j,:)<Vmin)) = Vmin;

        pop(j,:) = pop(j,:) + V(j,:);
        pop(j,find(pop(j,:)>popmax)) = popmax;
        pop(j,find(pop(j,:)<popmin)) = popmin;
        
        fitness(j) = fun(pop(j,:)); 
    end

    for j = 1:sizepop   
        if fitness(j) > fitnessgbest(j)
            gbest(j,:) = pop(j,:);      
            fitnessgbest(j) = fitness(j);
        end

        if fitness(j) > fitnesszbest
            zbest = pop(j,:);
            fitnesszbest = fitness(j);
        end
    end 
    yy(i) = fitnesszbest;     
end

[fitnesszbest zbest]
plot(zbest, fitnesszbest,\'r*\')

figure
plot(yy)
title(\'PSO：PSO算法(快于GA算法)+ω参数实现找到最优个体适应度—Jason niu\',\'fontsize\',12);
xlabel(\'进化代数\',\'fontsize\',12);ylabel(\'适应度\',\'fontsize\',12);