MATLAB Answers

Error in fmincon: undefined getIpOptions

479 views (last 30 days)
Lukas Meyerolbersleben
Lukas Meyerolbersleben on 25 Jul 2019
Commented: Navreet Singh Thind on 22 Feb 2021 at 14:07
Good evening,
I am trying to use fmincon to fit a multinomial tree model to behavioural data. I'm aware that other questions have been asked about the same error, but those questions haven't been resolved (see for example and wouldn't apply in my case anyway. Five parameters, each with the lower bound [0] and the upper bound [1], are to be estimated to minimize a G-squared estimate of goodness of fit (expressed in a customized function "Goodness_of_Fit_1", which itself works fine). No other constraints apply here, resulting in the following syntax:
fmincon(@Goodness_of_Fit_1, [0,0,0,0,0], [],[],[],[],[0,0,0,0,0],[1,1,1,1,1])
However, this returns the following error:
Undefined function or variable 'getIpOptions'.
Error in fmincon (line 811)
options = getIpOptions(options,sizes.nVar,mEq,flags.constr,defaultopt,10,0.01);
I am using Matlab R2018b and the path to fmincon is correct (uses the same version).
Thank you very much for your help!


Matt J
Matt J on 25 Jul 2019
What happens when you do
>> which -all getIpOptions
Lukas Meyerolbersleben
Lukas Meyerolbersleben on 25 Jul 2019
Then it returns:
'getIpOptions' not found.

Sign in to comment.

Answers (2)

Jim Hokanson
Jim Hokanson on 26 Nov 2019
I had this problem and just reinstalled the optimizaton toolbox ...

Matt J
Matt J on 25 Jul 2019
Well, it should be there. On my machine,
>> which -all getIpOptions
F:\Program Files\MATLAB\R2018b\toolbox\optim\optim\getIpOptions.m
I suggest you check your anti-virus software to see if it may have quarantined it. Then, I would do a complete clean re-install. By clean reinstall, I mean you first delete any existing R2018b folders.


Lukas Meyerolbersleben
Lukas Meyerolbersleben on 26 Jul 2019
Well, my anti-virus software didn't quarantine it. As soon as I've reinstalled Matlab, I'll post here whether that does the trick. In the meantime, thank you very much for your help!
Marcelo Fernandes
Marcelo Fernandes on 25 Nov 2019
For anyone having this problem, it appears to happen when you install a new version of MATLAB and uninstall the older versions from the computer - in this order. It could be that those files (such as getIpOptions.m) have not been installed because of previous files on the computer.
I followed Matt J's suggestion and it's fixed.
Thank you, Matt!

Sign in to comment.

Community Treasure Hunt

Find the treasures in MATLAB Central and discover how the community can help you!

Start Hunting!