stop=fminplot(pars, optimValues, state) default plotting function showing the criteria evolution as well as main parameters and status. A STOP button allows premature abortion of the optimization. To use this optimization monitoring tool, use: options.OutputFcn='fminplot' prior to the optimization/fit. To plot this monitoring window after the optimization/fit completion, use: [pars,fval,exitflag,output]=fmin(@objective, [], 'OutputFcn=fminplot') fminplot(output); To retrieve the optimisation history from the fminplot window, use: h = fminplot; Other defined function to be used as OutputFcn and PlotFcns: @fminstop displays a stop button (very fast, allow clean abort of fit) @optimplotx plots the current point @optimplotfval plots the function value @optimplotfunccount plots the function count example: fmin(@objective, [], 'OutputFcn=fminplot')