persistence of path when using mfilename

I have a script within a subfolder which is trying to reference the parent directory (two levels up), but am getting some unexpected behavior:

function varargout = myfun(varargin)

...

[myDir,~,~] = fileparts(mfilename('fullpath')); %this function directory

mainScriptDir = fullfile(myDir,'..','..'); %main script directory

...

%end myfun.m

end

the first time I run this I get something like

myDir = ...\parentDir\sub1\sub2 (myfun is located in sub2)

and the main script directory is '...\parentDir\..\..' which would be what I expect.

Subsequent calls yield:

myDir = ...\parentDir\sub1\sub2\..\..\sub1\sub2

myDir = ...\parentDir\sub1\sub2\..\..\sub1\sub2\..\..\sub1\sub2

etc.

Why does the path persist and continue to append with subsequent calls? Shouldn't the myfun workspace reset with each call? Is there a function I need to call to reset this behavior when using relative paths?

Thank you for your help!

Brian

[Walter Roberson]

Do you have a

cd(mainScriptDir)

?

[Brian]

No, nor does it seem to matter whether I call myfun from sub2,mainScriptDir, or some other folder.

[Walter Roberson]

Are you using mainScriptDir to construct a filename that you run() ?

Answer 1

[Image Analyst]

You aren't calling cd() in your program anywhere are you?

See the FAQ: https://matlab.wikia.com/wiki/FAQ#Where_did_my_file_go.3F_The_risks_of_using_the_cd_function.

[Brian]

Not currently, but eventually yes.

[Image Analyst]

I wouldn't. And you'll probably have to attach the script that demonstrates the problem, because it doesn't make sense.