Saving my own function to be used as MATLAB built-in functions

I would like to write a function that can be called from anywhere regardless of my current working path, just like I use integral(...) or sin(...). How should I change the setup to be able to do this?

[Jan]

You are a member of this forum for 2 years now and asked 44 questions. And this is the first time you want to add a user defined folder to the path? I cannot image how you can work with Matlab without saving files to folders in the path.

[Saeid]

Believe it or not, this is the first time I really need to do that.

Answer 1

[Ahmet Cecen]

Create a startup.m file in your MATLAB user folder(usually Documents/MATLAB) then use addpath in that file.

MATLAB will execute that file everytime it starts up, meaning the paths you specify in that file will be "permenantly" available in any folder for all intents and purposes. (At least for all cases someone asking this question will likely encounter.)

Answer 2

[the cyclist]

One way is to put any such functions into a particular directory (e.g. "utilities"), and then add that directory to the search path using the addpath command. I put the addpath command in my startup.m file, so it gets called every time I start MATLAB.

[Jan]

Instead of putting addpath to the startup file, you can use savepath or the GUI pathtool to store the folder permanently.

[Saeid]

I tried this:

savepath D:\Documents\MATLAB\Examples

and got this message:

Warning: Unable to save path to file 'D:\Documents\MATLAB\Examples'.
You can save your path to a different location by calling SAVEPATH
with an input argument that specifies the full path. For MATLAB to
use that path in future sessions, save the path to 'pathdef.m' in
your MATLAB startup folder. 
> In savepath (line 145)

[Jan]

A correct usage of savepath is:

addpath('D:\Documents\MATLAB\Examples', '-end');
savepath

Then the path is saved to the matlabroot folder, but this requires admin privilegs. Therefore it might be better to follow the advice given in the warning message: save the pathdef.m file to your startup folder - the folder which is active initially.

It is not clear, why the saving failed in your case. Is the folder existing and do you have write privileges?

[Saeid]

Thanks!