Can anyone suggest me to write a correct and working code for traveling salesman problem using simulated annealing? I got this but there are so many errors:
1 view (last 30 days)
Show older comments
% Travellingsalesman problem
% Create random city distribution
n=20;
x=random('unif',-1,1,n,1);
y=random('unif',-1,1,n,1);
gam=1; mu=sign(x);
% End up where you start. Add starting point to end
x=[x' x(1)]';
y=[y' y(1)]';
mu=[mu' mu(1)]'; figure(1); hold off; g=plot(x,y,'.r');
set(g,'MarkerSize',20);
c0=cost(x,y,mu,gam); k=1; % Boltzmanconstant
nt=50; nr=200; % nt: temp steps. nr: city switches each T cp=zeros(nr,nt);
iran=inline('round(random(d,1.5001,n+0.4999))','d','n');
for i=1:nt
T=1.0 -(i-1)/nt
for j=1:nr
% switch two random cities
ic1=iran('unif',n); ic2=iran('unif',n);
xs=x(ic1); ys=y(ic1); ms=mu(ic1);
x(ic1)=x(ic2); y(ic1)=y(ic2); mu(ic1)=mu(ic2);
x(ic2)=xs; y(ic2)=ys; mu(ic2)=ms;
p=random('unif',0,1); c=cost(x,y,mu,gam);
if (c < c0 | p < exp(-(c-c0)/(k*T))) % accept
c0=c;
else % reject and switch back
xs=x(ic1); ys=y(ic1); ms=mu(ic1);
x(ic1)=x(ic2); y(ic1)=y(ic2); mu(ic1)=mu(ic2);
x(ic2)=xs; y(ic2)=ys; mu(ic2)=ms;
end
cp(j,i)=c0;
end
figure(2); plot(reshape(cp,nt*nr,1)); drawnow;
figure(1); hold off; g=plot(x,y,'.r'); set(g,'MarkerSize',20); hold on;
plot(x,y,'b'); g=plot(x(1),y(1),'.g'); set(g,'MarkerSize',30);
p=plot([0 0],[-1 1],'r--'); set(g,'LineWidth',2); drawnow;
end
2 Comments
Accepted Answer
Walter Roberson
on 25 Feb 2013
That version of a random number routine is part of the Statistics Toolbox; see http://www.mathworks.com/help/stats/random.html
The Statistics Toolbox is optional extra cost for Academic and Professional licenses. It is, though, included in Student Version licenses, but the toolbox might not be installed by default.
16 Comments
More Answers (1)
See Also
Products
Community Treasure Hunt
Find the treasures in MATLAB Central and discover how the community can help you!
Start Hunting!