遗传算法求解tsp问题的matlab代码

p=rand(m,1);
[p1,I]=sort(p);
B=Ap(I,:)';
end
%=====================================================
function y=rshift(x,dir)
% Usage: y=rshift(x,dir)
% rotate x vector to right (down) by 1 if dir = 0 (default)
% or rotate x to left (up) by 1 if dir = 1
if nargin<2, dir=0; end
[m,n]=size(x);
if m > 1,
[csort,ridx]=sort(cost); % sort from small to big.
csum=sum(csort);
caverage=csum/ngpool;
cprobilities=caverage./csort;
copynumbers=0;removenumbers=0;
diffidx=find(sameidx==0);
if length(diffidx)<=2
gpool(2*i,:)=[1 randomize([2:12]')' 1];
end
end
%===========
%cross gens in couples
for i=1:ngpool/2
j=j-1;
t=X3(j);X3(j)=X3(i);X3(i)=t;
end
if X4(i)~=0,
k=k-1;
t=X4(k);X4(k)=X4(i);X4(i)=t;
end
end
for i=n1:n2
X3(2+i-n1)=X2(i);
X4(2+i-n1)=X1(i);
if nargin == 1,
rowcol=0;
end
if rowcol==0,
[m,n]=size(A);
p=rand(m,1);
[p1,I]=sort(p);
B=A(I,:);
elseif rowcol==1,
Ap=A';
[m,n]=size(Ap);
end
end
FARM=FARM(1:nn,:);
[aa,bb]=size(FARM);%交叉和变异
while aa<n
if nn<=2
nnper=randperm(2);
else
nnper=randperm(nn);
counter=0;
while counter<C
for i=1:n
len(i,1)=myLength(D,farm(i,:));%计算路径长度
end
maxlen=max(len);
minlen=min(len);
fitness=fit(len,m,maxlen,minlen);%计算归一化适应值
2048 1439
2496 3063 2805 1721 1172 0 676 2376 2187 1882
1813 1327
1821 2387 2129 1045 842 676 0 1700 1511 1206
1165 651
636 972 1622 1356 2542 2376 1700 0 189 494
end
elseif dir==0, % default rotate right or down
if col==0,
y = [x(n) x(1:n-1)];
elseif col==1 % column vector
y = [x(n); x(1:n-1)];
end
end
if n == 1,
col=1;
elseif n > 1,
error('x must be a vector! break');
end % x is a column vector
elseif m == 1,
if n == 1,
y=x; return
elseif n > 1,
end
L1=X3;L2=X4;
%=======================
其中distTSP.txt为10个城市距离矩阵。
0 622 1042 776 2236 2496 1821 636 825 1130
2005 1953
622 0 1608 1342 2802 3063 2387 972 1161 1166
0 514
1953 2519 2261 1177 1439 1327 651 1686 1497 1192
514 0
二。%TSP问题（又名：旅行商问题，货郎担问题）遗传算法通用matlab程序
%D是距离矩阵，n为种群个数,建议取为城市个数的1~2倍，
%C为停止代数，遗传到第 C代时程序停止,C的具体取值视问题的规模和耗费的时间而定
for i=1:ngpool,
if cprobilities(i)>1.1
copynumbers=copynumbers+1;
end
if cprobilities(i)<0.9
removenumbers=removenumbers+1;
end
end
copygpool=min(copynumbers,removenumbers);
2623 2519
1042 1608 0 1336 2544 2805 2129 1622 1811 2116
2313 2261
776 1342 1336 0 1451 1721 1045 1356 1545 1229
1229 1177
2236 2802 2544 1451 0 1172 842 2542 2353 2048
一Matlab的GA程序 遗传算法求TSP
for i=1:ngpool,
cost(i)=sum(diag(distance(gpool(i,:)',rshift(gpool(i,:))')));
end
% record current best solution
[costmin,idx]=min(cost);
end
%=========
%when genaration is more than 50,or the patterns in a couple are too close,do
mutation
for i=1:ngpool/2
%
sameidx=[gpool(2*i-1,:)==gpool(2*i,:)];
%==================================================
function [L1,L2]=crossgens(X1,X2)
% Usage:[L1,L2]=crossgens(X1,X2)
s=randomize([2:12]')';
n1=min(s(1),s(11));n2=max(s(1),s(11));
rr=find(len==minlen);
R=farm(rr(1,1),:);%更新最短路径
FARM=farm;%优胜劣汰，nn记录了复制的个数
nn=0;
for i=1:n
if fitness(i,1)>=alpha*rand
nn=nn+1;
FARM(nn,:)=farm(i,:);
end
disp(['cost function evaluation: ' int2str(increase) ' times!'])
disp(['n:' int2str(resultincrease)])
disp(['minmum trip length = ' num2str(resultcost)])
[N,NN]=size(D);
farm=zeros(n,N);%用于存储种群
for i=1:n
farm(i,:)=randperm(N);%随机生成初始种群
end
R=farm(1,:);%存储最优种群
len=zeros(n,1);%存储路径长度
fitness=zeros(n,1);%存储归一化适应值
[gpool(2*i-1,:),gpool(2*i,:)]=crossgens(gpool(2*i-1,:),gpool(2*i,:));
end
for i=1:ngpool,
cost(i)=sum(diag(distance(gpool(i,:)',rshift(gpool(i,:))')));
disp('optimum tour = ')
disp(num2str(resulttour))
%====================================================
function B=randomize(A,rowcol)
% Usage: B=randomize(A,rowcol)
% randomize row orders or column orders of A matrix