I want to terminate the program when route distance becomes 75. But in command window program keeps running till the condition of iterations is achieved.

function genetic4()

           xy =[

    6.9409    0.2259

 1.7989    5.2270
    3.1137    4.5593

    8.8533    3.2828

    7.6421    0.9238

    5.0609    5.2346

    3.0046    9.0919

    8.6061    8.6808

    2.0093    5.1440

    4.3699    2.3990

    9.8835    3.0795

    9.0423    3.9674

    5.7818    1.1668

    7.7035    2.2236

    7.6342    0.8472

    5.5940    9.9058

    7.0005    5.8606

    4.8557    6.3250

    4.7683    1.9913

    7.4014    1.7087

    7.4623    4.4927

    2.0258    4.0282

    0.8051    1.0827

    7.0566    1.7103

    4.4705    6.1112

    3.4823    4.9517

    1.4722    2.7032

    9.2913    3.0202

    3.8684    0.0541

    7.6120    0.0102

    0.5414    5.1897

    8.7149    2.4217

    7.1843    0.8910

    6.1193    6.3243

    0.6303    8.1332 ];

            N = size(xy,1);

         a = meshgrid(1:N);

            distance_matrix = reshape(sqrt(sum((xy(a,:)-xy(a',:)).^2,2)),N,N);

            population = 100;

            iterations = 1e4;

figure('Name','City Locations','Numbertitle','on');

        plot(xy(:,1),xy(:,2),'k.');

[nr,nc] = size(distance_matrix);

if N ~= nr N ~= nc

    error('Invalid XY or distance_matrix inputs!')

end

n = N;

population = 4*ceil(population/4);

iterations = max(1,round(real(iterations(1))));

pop = zeros(population,n);

for k = 1:population

    pop(k,:) = randperm(n);

end

global_min = Inf;

total_dist = zeros(1,population);

dist_history = zeros(1,iterations);

tmp_pop = zeros(4,n);

new_pop = zeros(population,n);

    pfig = figure('Name','genetic | Current Best

Solution','Numbertitle','off');

for iter = 1:iterations

    for p = 1:population

        d = distance_matrix(pop(p,n),pop(p,1));

        for k = 2:n
            d = d + distance_matrix(pop(p,k-1),pop(p,k));

        end

        total_dist(p) = d;

    end

    [min_dist,index] = min(total_dist);

    dist_history(iter) = min_dist;

    if min_dist < global_min

        global_min = min_dist;

         if global_min>75.000

        % global_min = 80.152;

        best_route = pop(index,:);

            figure(pfig);

route = best_route([1:n 1]);

            plot(xy(route,1),xy(route,2),'r.-');

            title(sprintf('Total Distance = %1.4f, Iteration =

%d',min_dist,iter));

         end
    end

      rand_pair = randperm(population);

      for p = 4:4:population

        routes = pop(rand_pair(p-3:p),:);

        dists = total_dist(rand_pair(p-3:p));

        [~,idx] = min(dists);

        best_of_4_route = routes(idx,:);

        ins_pts = sort(ceil(n*rand(1,2)));

        I = ins_pts(1);

        J = ins_pts(2);

        for k = 1:4

            tmp_pop(k,:) = best_of_4_route;

            switch k
                case 2 

                    tmp_pop(k,I:J) = fliplr(tmp_pop(k,I:J));
                case 3
                    tmp_pop(k,[I J]) = tmp_pop(k,[J I]);

                case 4
                    tmp_pop(k,I:J) = tmp_pop(k,[I+1:J I]);

    otherwise

            end
            display(best_of_4_route);

             display(d);

        end

           new_pop(p-3:p,:) = tmp_pop;
    end

    pop = new_pop;
end
end

[Jan]

Please learn how to format code in the forum. A blank line after each line of code reduces the readability. The indentation can be cleaned automatically by Matlab's editor (mark bloc, Ctrl-I).

Answer 1

[Jan]

It is not a good idea to let us guess, in which lines you want to perform "I want to terminate the program when route distance becomes 75". I find:

if global_min>75.000
  ...
end

But there is no trial to terminate the program, as far as I can see. Do you want to add a return command there?

[Sanuj Shukla]

My program finds routes and optimizes them according to path length. My purpose of terminating at

     global_min>75

was to find the route which has length more than 75. But I am unable to store whole work space by

    % save('d')

(all routes, all distances etc). It only stores final route and final path length. What should I use to store it.