Plot function value vs 2 variables (expecting 3D plot) for each iteration in fmincon

Question

Yurii Iotov 2019-6-19

0
链接

此问题的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/467887-plot-function-value-vs-2-variables-expecting-3d-plot-for-each-iteration-in-fmincon

Hi

I need to plot for each iteration fval as Z, vs optimal values x from fmincon at this iteration

I tried to do it with Output Function Syntax and Plot Function Syntax in matlab doc and wrote(adapt) this code, but I get just a empty figure...

options = optimoptions('fmincon','PlotFcns',@optim_plot_fval_vs_q);
[x_opt, fval, exitflag, output, lambda_fmincon, grad, hessian]...
        = fmincon(@objectiveFunction, x0, [],[],[],[],[],[], @nonlincon, options);
    
function stop = optim_plot_fval_vs_q(x,optimValues,state,varargin)
% OPTIMPLOTRESNORM Plot value of the norm of residuals at each iteration.
%
%   STOP = OPTIMPLOTRESNORM(X,OPTIMVALUES,STATE) plots OPTIMVALUES.resnorm.
%
%   Example:
%   Create an options structure that will use OPTIMPLOTRESNORM as the plot
%   function
%     options = optimoptions('lsqnonlin','PlotFcn',@optimplotresnorm);
%
%   Pass the options into an optimization problem to view the plot
%     lsqnonlin(@(x) sin(3*x),[1 4],[],[],options);
%   Copyright 2006-2015 The MathWorks, Inc.
persistent plotavailable
stop = false;
switch state
      case 'init'
          if isfield(optimValues,'resnorm')
            plotavailable = true;
          else
              plotavailable = false;
              title(getString(message('optim:optimplot:TitleNormResid', ...
                     getString(message('optim:optimplot:NotAvailable')))),'interp','none');
         end
    case 'iter'
        if plotavailable
            if optimValues.iteration == 0
                % The 'iter' case is  called during the zeroth iteration,
                % but it now has values that were empty during the 'init' case
%                 plotresnorm = plot(optimValues.iteration,optimValues.resnorm,'kd', ...
%                     'MarkerFaceColor',[1 0 1]);
                plotresnorm = plot3(x(1), x(length(x)/2+1), optimValues.fval);
%                 xlabel(getString(message('optim:optimplot:XlabelIter')),'interp','none');
%                 set(plotresnorm,'Tag','optimplotresnorm');
%                 ylabel(getString(message('optim:optimplot:YlabelNormResid')),'interp','none');
%                 title(getString(message('optim:optimplot:TitleNormResid', ...
%                     sprintf('%g',norm(optimValues.resnorm)))),'interp','none');
            else
%                 plotresnorm = findobj(get(gca,'Children'),'Tag','optimplotresnorm');
%                 newX = [get(plotresnorm,'Xdata') optimValues.iteration];
%                 newY = [get(plotresnorm,'Ydata') optimValues.resnorm];
%                 set(plotresnorm,'Xdata',newX, 'Ydata',newY);
                
                newX = [get(plotresnorm,'Xdata') x(1)];
                newY = [get(plotresnorm,'Ydata') x(length(x)/2+1)];
                newZ = [get(plotresnorm,'Zdata') optimValues.fval];
                set(plotresnorm,'Xdata',newX, 'Ydata',newY, 'Zdata',newZ);
                
%                 set(get(gca,'Title'),'String', ...
%                     getString(message('optim:optimplot:TitleNormResid', ...
%                     sprintf('%g',optimValues.resnorm))));
            end
        end
end