Function in MATLAB's path not call-able by another function in MATLAB's path despite both functions being call-able in Command Window

I have a function, "cmap", that refuses to be called by another function "mproc", though both are in MATLAB's path (I have repeatedly verified that both functions are in folders in MATLAB's path). "mproc" runs fine and can call other functions that are not "cmap", but when it gets to cmap I get one of two errors, copied and commented below:

% 'cmap' is not found in the current folder or on the MATLAB path, but exists in:
    % C:\Users\my_name\Documents\MATLAB\Image Processing\Cmap functions
    
% Change the MATLAB current folder or add its folder to the MATLAB path.

or

% Unrecognized function or variable 'cmap'.

The folder that it's in IS on the MATLAB path, however. Even so, when I click "add its folder to the MATLAB path" anyways, the same error persists when I try to use it again.

This is particularly confusing because I can call "cmap" in the Command Window (since it's in MATLAB's path). I was not having this issue earlier today but suddenly MATLAB just refuses to use "cmap" in "mproc". Am I missing something completely obvious?

Here is a picture of my MATLAB, showing "cmap" in a folder that is on the MATLAB path, mproc is in the "Image stack functions" folder (also in MATLAB's path). I have highlighted the line of code where the program breaks and an error message is displayed below.

[Lars Nelson]

Additionally, I just found that the function "cmap" can be called from mproc in a different line of code. So this specific line of code is just refusing to work for seemingly no reason. If you see the reason please let me know!

[Cris LaPierre]

You've ruled out the main culprits I would suspect. Does this go away after restarting MATLAB? Is this behavior reproducible on other machines?

[Lars Nelson]

It did not go away after re-starting MATLAB, no. I don't have another machine to test it on, unfortunately.

Answer 1

[Lars Nelson]

I changed the name of the cmap function to createcmap and that seems to have fixed it. Not sure why MATLAB suddenly decided that this function name was not allowed as it had been working half an hour before I encountered the issue.

[Cris LaPierre]

Please consider reporting this here: https://www.mathworks.com/support/contact_us.html

Answer 2

[Matt J]

So this specific line of code is just refusing to work for seemingly no reason.

Maybe there is some invisible character in that line that is corrupting the call? Try deleting the whole line and retyping it.

[Lars Nelson]

This did not work, sadly.

Answer 3

[Matt J]

Possibly mproc or one of its callers has path-altering commands that temporarily remove cmap from the path. To be certain, we would need you to set a breakpoint at line 719 and display the path only after execution pauses there.