Error in the use of fminunc function

Hello everyone,

in the following there is my matlab code:

>> fun = @(x)3*x(1)^2 + 2*x(1)*x(2) + x(2)^2 - 4*x(1) + 5*x(2);

>> x0 = [1,1];

>> [x,fval] = fminunc(fun,x0);

and this is the error that I have:

Unable to load a message catalog 'optim:fminusub'. Please check the file location and format.

Error in createExitMsg (line 32)

basicMsg = getString(message(basicMsgArgs{:}));

Error in fminusub (line 322)

output.message = createExitMsg(msgData{:});

Error in fminunc (line 496)

[x,FVAL,GRAD,HESSIAN,EXITFLAG,OUTPUT] = fminusub(funfcn,x, ...

Someone can help me to solve this problem?

Thak you a lot

Answer 1

[Torsten]

Put your three lines of code in a script file, call it "test.m", load it in the MATLAB editor and execute the script by the green RUN arrow. Does it work now ?

Steven Lord's answer given here might help if this is not the case:

https://uk.mathworks.com/matlabcentral/answers/1443459-error-in-fminunc-function-line-477

[Silvia]

Hi Torsten, I tried to put my lines in a script but it doesn't work. I also read Steven Lord's answer, but it doesn't help me.

[Torsten]

What does MATLAB return to the command

license('checkout','optimization_toolbox')

?

What do you get when you type

which -all fminunc

?

[Silvia]

license('checkout','optimization_toolbox')
1
which -all fminunc
C:\Program Files\MATLAB\R2023a\toolbox\shared\optimlib\fminunc.m

thaks for your help

[Torsten]

Did you make any changes to your MATLAB installation ? Modified or deleted files ? Mixed files from different releases ?

If not, you should contact Technical Support:

https://uk.mathworks.com/support/contact_us.html

Answer 2

[Matt J]

I would try a clean re-install of Matlab (i.e., deleting all installation folders that may have been created).