How to add variables to the Plot Fcn?

I created a custom Plot Function for 'fminsearch':

opts = optimset('Display','iter','TolFun',1e-5,'MaxIter',100,'PlotFcns',@outf);
[v1, fval] = fminsearch(funtol,v1,opts);

function stop = outf(x, optimValues, state)
...<Plot some stuff>...
end

How can I add some variables to the Plot Function? For example:

function stop = outf(x, optimValues, state, var1, var2)

I don't know how to call it then in 'optimset' properly, because, it seems, there are no additional varibles allowed:

opts = optimset('PlotFcns',@outf<Don't know what to write here>);

Answer 1

[Adam Danz]

One solution is to write an anonymous function and define the extra values prior to creating the anonymous function. Those extra values will then be stored in that function until it's deleted or overwritten. Example:

% Assuming your outf function is within the function or script
var1 = 0; 
var2 = 1; 
outfAnon = @(x) outf(x, optimValues, state, var1, var1);

opts = optimset('PlotFcns',outfAnon, ...)

For more information on this method or to see other methods including the use of nested functions and global vars (avoid), see this : https://www.mathworks.com/help/optim/ug/passing-extra-parameters.html

[EDIT] Removed a mistake where I included ' @' symbol when entering outfAnon in the opts line.

[Denis Perotto]

That didn't help.

This one works:

clc; close all; clear;

f = @(x) (1-x(1)).^2+100.*(x(2)-x(1).^2).^2;
x0 = [2 2];

opts = optimset('Display','iter','TolX',1e-5,'PlotFcn',@outf);
[x1, f1] = fminsearch(f, x0, opts);

function stop = outf(x, optimValues, state)
    stop = false;
end

This one, as you suggested, doesn't:

clc; close all; clear;

f = @(x) (1-x(1)).^2+100.*(x(2)-x(1).^2).^2;
x0 = [2 2];

var = 1;
outfanon = @(x, optimValues, state) outf(x, optimValues, state, var);

opts = optimset('Display','iter','TolX',1e-5,'PlotFcn',@outfanon);
[x1, f1] = fminsearch(f, x0, opts);

function stop = outf(x, optimValues, state, var)
    stop = false;
end

I get

Error: File: fmintest.m Line: 9 Column: 57
"outfanon" was previously used as a variable, conflicting with its use here as the name of a function or command.
See "How MATLAB Recognizes Command Syntax" in the MATLAB documentation for details.

[Adam Danz]

Your implementation of my suggestion didn't work because you used '@' when calling outfanon (which I also mistakenly did in my example). The '@' symbol defines an anonymous function. When you use the function handle you shouldn't include that symbol.

If you remove that and use this line instead, the code works.

opts = optimset('Display','iter','TolX',1e-5,'PlotFcn',outfanon);

Answer 2

[Alan Weiss]

Perhaps you are looking for how to pass extra parameters.

Alan Weiss

MATLAB mathematical toolbox documentation