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MATLAB代码:
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5 X" {5 J! G5 f/ h$ I8 z- \0 `4 U8 v- %------初始格式化--------------------------------------------------
- clear all;
- clc;
- format long;
- %------给定初始化条件----------------------------------------------
- c1=2; %学习因子1
- c2=2; %学习因子2
- w=0.7298; %惯性权重
- MaxDT=200; %最大迭代次数
- % D=2; %搜索空间维数(未知数个数)
- N=20; %初始化群体个体数目
- %eps=10^(-6); %设置精度(在已知最小值时候用)
- Vmax=1;
- Vmin=-1;
- popmax=5;
- popmin=-5;
- %------初始化种群的个体(可以在这里限定位置和速度的范围)------------
- for i=1:N
- pop(i,:)=popmin+(popmax-popmin)*rand(1,2); %随机初始化位置
- V(i,:)=rand(1,2); %随机初始化速度
- fitness(i)=ackley(pop(i,:));
- end
- %------先计算各个粒子的适应度,并初始化Pi和Pg----------------------
- [fitnessgbest bestindex]=min(fitness);
- gbest=pop(bestindex,:);
- pbest=pop;
- fitnesspbest=fitness;
- for i=1:MaxDT
- for j=1:N
- V(j,:)=w*V(j,:)+c1*rand*(pbest(j,:)-pop(j,:))+c2*rand*(gbest-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;
- % if rand>0.8
- % k=ceil(2*rand);
- % pop(j,k)=rand;
- % end
- fitness(j)=ackley(pop(j,:));
- if fitness(j)<fitnesspbest(j)
- pbest(j,:)=pop(j,:);
- fitnesspbest(j)=fitness(j);
- end
- if fitness(j)<fitnessgbest
- gbest=pop(j,:);
- fitnessgbest=fitness(j);
- end
- end
- yy(i)=fitnessgbest;
- end
- %------最后给出计算结果
- plot(yy)
- title(['适应度曲线 ' '终止次数=' num2str(MaxDT)]);
- xlabel('进化代数');
- ylabel('适应度')
- %------算法结束---DreamSun GL & HF-----------------------------------+ ~* J: r3 \/ u. {
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5 `" q" e9 F4 O0 ~ D8 ?! y优化的函数为ackley函数:$ p, }2 u4 c4 c$ t, K9 V
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- % ackley.m
- % Ackley's function, from http://www.cs.vu.nl/~gusz/ecbook/slides/16
- % and further shown at:
- % http://clerc.maurice.free.fr/pso ... nuous_challenge.htm
- %
- % commonly used to test optimization/global minimization problems
- %
- % f(x)= [ 20 + e ...
- % -20*exp(-0.2*sqrt((1/n)*sum(x.^2,2))) ...
- % -exp((1/n)*sum(cos(2*pi*x),2))];
- %
- % dimension n = # of columns of input, x1, x2, ..., xn
- % each row is processed independently,
- % you can feed in matrices of timeXdim no prob
- %
- % example: cost = ackley([1,2,3;4,5,6])
- function [out]=ackley(in)
- % dimension is # of columns of input, x1, x2, ..., xn
- n=length(in(1,:));
- x=in;
- e=exp(1);
- out = (20 + e ...
- -20*exp(-0.2*sqrt((1/n).*sum(x.^2,2))) ...
- -exp((1/n).*sum(cos(2*pi*x),2)));
- return
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' r3 B6 B# E6 q; ~函数图像:
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其它代码:
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- u: y9 C- |8 t+ ]# V3 k7 L- clear;
- clc;
- format long;
- %------给定初始化条件----------------------------------------------
- c1=2; %学习因子1
- c2=2; %学习因子2
- w=0.7; %惯性权重
- MaxDT=100; %最大迭代次数
- D=1; %搜索空间维数(未知数个数)
- M=30; %初始化群体个体数目
- eps=10^(-6); %设置精度(在已知最小值时候用)
- %------初始化种群的个体(可以在这里限定位置和速度的范围)------------
- x=randn(M,D); %随机初始化位置
- v=randn(M,D); %随机初始化速度
- %------先计算各个粒子的适应度,并初始化p(i)和gbest--------------------
- for i=1:M
- p(i)=fitness(x(i,:),D);
- y(i,:)=x(i,:);
- end
- gbest=x(1,:); %gbest为全局最优
- for i=2:M
- if(fitness(x(i,:),D)<fitness(gbest,D))
- gbest=x(i,:);
- end
- end
- %------进入主要循环,按照公式依次迭代,直到满足精度要求------------
- for t=1:MaxDT
- for i=1:M
- v(i,:)=w*v(i,:)+c1*rand*(y(i,:)-x(i,:))+c2*rand*(gbest-x(i,:));
- x(i,:)=x(i,:)+v(i,:);
- if fitness(x(i,:),D)<p(i)
- p(i)=fitness(x(i,:),D);
- y(i,:)=x(i,:);
- end
- if p(i)<fitness(gbest,D)
- gbest=y(i,:);
- end
- end
- end
- %------显示计算结果
- disp('*************************************************************')
- disp('函数的全局最优位置为:')
- Solution=gbest'
- disp('最后得到的优化极值为:')
- Result=fitness(gbest,D)
- disp('*************************************************************')
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