Error every time the PDE toolbox is used

Hello everyone,

I'm trying to use the PDE toolbox for the first time, to solve some simple PDEs. Since i'm a novice, I thought I'd use the app to do so; however, i'm having problems to use it. Every time i try to solve a PDE, i get the following error message:

Undefined function 'isnan' for input arguments of type 'u'.

This has happened every time i tried to use the toolbox, even when i scrupolously followed the examples given in the toolbox documentation.

I've already tried to uninstall and reinstall the toolbox to no avail. I'm using Matlab 2015b.

Does anyone have any insights into this? Thanks.

Answer 1

[Nachiket Katakkar]

Hi Matteo,

This sort of an error usually occurs when a user defined function shadows an in-built MATLAB function. This is discussed in greater detail in the following MATLAB Answers post:

https://www.mathworks.com/matlabcentral/answers/96005-why-do-i-get-the-error-undefined-function-or-variable

Make sure that the license checks out:

>> status = license('checkout','PDE_Toolbox')

Clear path issues using the following commands:

>> restoredefaultpath
>> rehash toolboxcache
>> savepath