MATLAB: Errors in solving nonlinear simultaneous equations

fsolveMATLABnonlinear

Hello all, I'm trying to solve nonlinear simultaneous equations. However, Matlab is giving errors, which I cannot rectify. Any help is much appreciated.
I made a function file:
function [ f ] = nlsimul( x)
%nlsimul has two nonlinear simultaneous equations in variable x(1), x(2)
f = [-2*(x(1).^2).*exp(-x(1).^2-(x(2).^2))+exp(-x(1).^2-(x(2).^2)); ...
    -2.*x(1).*x(2)*exp(-x(1).^2-(x(2).^2))];
end
Then I made a script file to solve this system of equations:
%This script calles nlsimul() to solve nonlinear simultaneous equations
options = optimoptions('fsolve','Diagnostics','on','Display','iter','PlotFcns','@optimplotresnorm');
x0=[2,2];
[x,fval,exitflag,output] = fsolve(@nlsimul,x0,options)
Upon running this script file, Matlab gives several errors. Can someone help?

Best Answer

You can't plot a simultaneous equation during iterations in that way.
If you instead put:
options = optimoptions('fsolve','Diagnostics','on','Display','iter');
Then your optimisation runs perfectly.
If you instead put (note the function handle rather than string):
options = optimoptions('fsolve','Diagnostics','on','Display','iter','PlotFcns',@optimplotresnorm);
Then it solves fine as well... it's too quick to see anything plotted though...
Did that help you out?
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