www.gusucode.com > globaloptim 案例源码程序 matlab代码 > globaloptim/gaplotshowpopulation2.m

    function state = gaplotshowpopulation2(~,state,flag,fcn)
%gaplotshowpopulation2 Plots the population and linear constraints in 2-d.
%   STATE = gaplotshowpopulation2(OPTIONS,STATE,FLAG) plots the population
%   in two dimensions.
%
%   Example:
%     fun = @lincontest6;
%     options = gaoptimset('PlotFcn',{{@gaplotshowpopulation2,fun}});
%     [x,fval,exitflag] = ga(fun,2,A,b,[],[],lb,[],[],options);

% This plot function works in 2-d only
if size(state.Population,2) > 2
    return;
end
if nargin < 4
    fcn = [];
end
% Dimensions to plot
dimensionsToPlot = [1 2];

switch flag
    % Plot initialization
    case 'init'
        pop = state.Population(:,dimensionsToPlot);
        plotHandle = plot(pop(:,1),pop(:,2),'*');
        set(plotHandle,'Tag','gaplotshowpopulation2')
        title('Population plot in two dimension','interp','none')
        xlabelStr = sprintf('%s %s','Variable ', num2str(dimensionsToPlot(1)));
        ylabelStr = sprintf('%s %s','Variable ', num2str(dimensionsToPlot(2)));
        xlabel(xlabelStr,'interp','none');
        ylabel(ylabelStr,'interp','none');
        hold on;
       
        % plot the inequalities
        plot([0 1.5],[2 0.5],'m-.') %  x1 + x2 <= 2
        plot([0 1.5],[1 3.5/2],'m-.'); % -x1 + 2*x2 <= 2
        plot([0 1.5],[3 0],'m-.'); % 2*x1 + x2 <= 3
        % plot lower bounds
        plot([0 0], [0 2],'m-.'); % lb = [ 0 0];
        plot([0 1.5], [0 0],'m-.'); % lb = [ 0 0];
        set(gca,'xlim',[-0.7,2.2])
        set(gca,'ylim',[-0.7,2.7])
        axx = gcf;
        % Contour plot the objective function
        if ~isempty(fcn)
            range = [-0.5,2;-0.5,2];
            pts = 100;
            span = diff(range')/(pts - 1);
            x = range(1,1): span(1) : range(1,2);
            y = range(2,1): span(2) : range(2,2);

            pop = zeros(pts * pts,2);
            values = zeros(pts,1);
            k = 1;
            for i = 1:pts
                for j = 1:pts
                    pop(k,:) = [x(i),y(j)];
                    values(k) = fcn(pop(k,:));
                    k = k + 1;
                end
            end
            values = reshape(values,pts,pts);
            contour(x,y,values);
            colorbar
        end
        % Show the initial population
        ax = gca;
        fig = figure;
        copyobj(ax,fig);colorbar
        % Pause for three seconds to view the initial plot, then resume
        figure(axx)
        pause(3);
    case 'iter'
        pop = state.Population(:,dimensionsToPlot);
        plotHandle = findobj(get(gca,'Children'),'Tag','gaplotshowpopulation2');
        set(plotHandle,'Xdata',pop(:,1),'Ydata',pop(:,2));
end