How to suppress warnings from fsolve method?

Hello,

how to suppress these kind of warnings for the fsolve method? It is orange by the way.

Warning: Trust-region-dogleg algorithm of FSOLVE cannot handle non-square systems; using Levenberg-Marquardt algorithm instead. 
> In fsolve (line 298)
  In function1 (line 24)
  In mainScript (line 265)

Thank you!

Answer 1

[Jan]

The message means, that the default choise of the Trust-region-dogleg method is not suffcient.

The best way to suppress a warning is to fix the reason. If you know in advance, that you need a Levenberg-Marquardt algorithm, enable it explicitely instead of letting fsolve examine the problem by its own. See https://www.mathworks.com/help/optim/ug/fsolve.html#inputarg_options .

[Manuela Gräfe]

Actually I know what I am doing and the warning isn't interesting to me. I was just wondering if it's possible to suppress it.

[Torsten]

As Jan suggests, enable the algorithm explicitly:

options = optimoptions('fsolve','Algorithm','levenberg-marquardt');
x = fsolve(fun,x0,options)

Best wishes

Torsten.

[Manuela Gräfe]

Hi Torsten, yes, thank you. I understand Jan's and yours suggestion. But that's not what I am exactly looking for. Is it possible to mute warnings from fsolve in general?

[Walter Roberson]

What benefit is being derived from not passing in the Algorithm option?

[Jan]

@Manuela: It is possible to suppress warning messages, see doc warning . But it is a bad idea to ignore warnings. Even if you now know, what you are doing, your program might change in the future. Your data might be delivered as square matrix by accident and then a completely different solver is used. This might have unexpected consequences.

Answer 2

[Alan Weiss]

Sounds like you are interested in learning how to suppress warnings.

Alan Weiss

MATLAB mathematical toolbox documentation

[Walter Roberson]

In particular, the ID is optim:fsolve:NonSquareSystem