Error using optimset(@lsqnonlin) matlab 2020b

Hi,

I'm having trouble using optimset () for lsqnonlin () function. I am using matlab version 2020b.

...

options = optimset(@lsqnonlin)
X = lsqnonlin('filtroRC', X0, [], [], options, Vin, t, Vout_e)

...

Error using optimset (line 163)

No default options available for the function 'lsqnonlin'.

I would appreciate suggestions

Answer 1

[Walter Roberson]

Wrong options routine for that function. You need https://www.mathworks.com/help/optim/ug/optim.problemdef.optimizationproblem.optimoptions.html

[Juan Gómez]

Thank you very much for the answer, but even using the suggested function, it returns error. Instead of evaluation in matlab online it returns ok, I think the problem is the 2020b version of matlab that I use.

>> options = optimoptions(@lsqnonlin,'Algorithm','levenberg-marquardt',...
    'MaxFunctionEvaluations',1500)

Error using optimoptions (line 124)
Invalid solver specified. Provide a solver name or handle (such as 'fmincon' or @fminunc).
Type DOC OPTIMOPTIONS for a list of solvers.

Obs: The first 2 examples of the suggested link, return ok too, both in matlab online and on my computer.

options = optimoptions ('fmincon')

and

options = optimoptions (@ fmincon, 'Algorithm', 'sqp', 'MaxIterations', 1500)

however, I appreciate any other suggestions!!

[Walter Roberson]

Ah... I suspect you do not have the Optimization Toolbox installed (or licensed perhaps.)

[Juan Gómez]

I installed the plugin, problem solved. Thanks a lot!!

[Yi Zhao]

Hello, Gómez. What is the plug-in you installed

[Juan Gómez]

Hi, was the Optimization Toolbox, just browse from matlab itself:

Add-Ons > Get Add-Ons > Optimization Toolbox