Calling user defined function anywhere? (matlab) - matlab

Where can i save my document "function.m", so i can call this function from any code in any path of my pc?
I already made some custom functions, but i dont know where to save those codes to be able to call them from any part.

Save them in a logical place where you can find them back. Then, use addpath to add that folder to MATLAB's search path, i.e. when you use a function it will try that folder as well to find it.
You can do this either per script, or edit startup.m with this, so that it's automatically included when MATLAB starts.

Alternatively to Adriaan's best practice answer, the fastest option is to save your function.m in the %USERPROFILE%/Documents/MATLAB directory on your PC ($home/Documents/MATLAB on Linux and Mac). This directory is on your MATLAB Search Path by default. This might be an acceptable solution if you use the function commonly across different projects.
Finally, there is a "manual" solution: Execute pathtool in MATLAB, add the directory containing your function.m via the GUI and hit save.

Related

setting a default matlab path at startup

My team is trying to standardise our Matlab paths so that everyone has the same.
I have a list of the default matlab path that we should all have.
So we would like to have a script that runs when matlab opens to make sure that our paths are set to the default matlab path. So if a path has been added to our default list it will be added in the correct place.
Is this possible in Matlab?
I read about startup but that seems to do with set your working directory which is different to what I am trying to do.
You can change which directory MATLAB starts in using the userpath function so that whenever you start up MATLAB, the path will automatically redirect here.
This may be useful if you have MATLAB running on a network per se, and multiple instances can start in the same network directory.
See more from MathWorks here: http://www.mathworks.com/help/matlab/matlab_env/matlab-startup-folder.html
However, if you want to standardize everything so that everyone has access to the same path, you can use startup to add directories / folders to MATLAB's path, but if you want to complete the package, use userpath to get MATLAB to start at a specified directory.
Your startup.m file may look something like this:
addpath('/folder/to/add/one');
addpath('/folder/to/add/two');
addpath('/folder/to/add/three');
addpath('/folder/to/add/four');
Then set your userpath with the function to complete everything:
userpath('/folder/to/start');
addpath('/folder/to/start');
Also make sure you add this new folder to your startup.m file too.
Include a path or addpath line in file startup.m. For example, to add folder aaa\bbb to the path the line would be
addpath('aaa\bbb')
Note that each user may have a different startup.m file. You may need to create it, if it doesn't already exist.

matlab creating paths to stop copying code

I have created a few general function in MATLAB that I intend to use for a few separate projects. However I do not want to copy the function into each separate project function.
I have created a folder called Misc_Function when I have placed these general functions. I know I can reference this functions explicitly by using the path and function name when trying to call the functions.
I believe you can add a path (in my case 'H:\MyTeam\Matlab\Misc_Function') when MATLAB loads up is that correct and if so how do you do this?
Assuming the above can be done I'm interested to know how MATLAB finds the correct function. In my understanding (guess work) MATLAB has a list of paths that it check trying to find a function with the name specified - is that correct? If so what happens when there are functions with the same name?
MATLAB indeed has its own search path which is a collection of folders that MATLAB will search when you reference a function or class (and a few other things). To see the search path, type path at the MATLAB prompt. From the documentation:
The order of folders on the search path is important. When files with the same name appear in multiple folders on the search path, MATLAB uses the one found in the folder nearest to the top of the search path.
If you have a set of utility functions that you want to make available to your projects, add the folder to the top of the search path with the addpath function, like so
addpath('H:\MyTeam\Matlab\Misc_Function');
You have to do this everytime you start MATLAB. Alternatively, and more conveniently, save the current search path with the savepath command or add the above commands to your startup.m file.
You can check the actual paths where Matlab searches for functions using
path
You will notice, that the most top path (on start up) is a path in your home folder. For Linux this is e.g. /home/$USER/Documents/MATLAB. For Windows it is somewhere in the the c:\Users\%USER%\Documents\Matlab (I think). Placing a file startup.m in this folder allows to add additional paths using
addpath('H:\MyTeam\Matlab\Misc_Function');
or
addpath(genpath('H:\MyTeam\Matlab\Misc_Function'));
on start up of Matlab. The latter (genpath) allows to also add all subdirectories. Simply write a file startup.m and add one of above lines there.
I believe 'addpath' will add the folder to MATLAB path only for the current MATLAB session. To save the updated path for other sessions, you need to execute 'savepath' command.
As mentioned in the previous comments, adding the folder in startup.m is a good idea since it will be added to the path on MATLAB startup.
To answer your question about how MATLAB finds the correct function, MATLAB maintains a list of directories in its path in a file called pathdef.m. Any changes to the path will be written to this file (when you execute 'savepath'). The path variable is initialized with the contents of this file.

automatically add path in a MATLAB script

I have several MATLAB scripts to share with my colleagues. I have put these scripts under a specified directory, e.g., /home/sharefiles
Under the MATLAB command prompt, the users can use these scripts by typing
addpath /home/sharefiles
Is there a way to automatically add this path in my matlab script, and save users the efforts of invoking addpath /home/sharefiles each time.
Sure, just add the addpath to your script.
addpath('/home/sharefiles')
If you want to recursively add subdirectories, use the genpath function:
addpath(genpath('/home/sharefiles')
Adding files to the path or one of the slower operations in Matlab, so you probably don't want to put the addpath call in the inner loop of an operation. You can also test to see if you need to add the path first.
if ~exist('some_file_from_your_tools.m','file')
addpath('/home/sharefiles')
end
Or, more directly
if isempty(strfind(path,'/home/sharefiles;'))
addpath('/home/sharefiles')
end
You could add the code posted by Pursuit to your startup.m file so that MATLAB adds it to the path automaticlly upon startup. Or, take a look at the savepath function. Lastly,
So when you Use the GUI to set path, the paths get added in the default start directory of Matlab in the pathdef.m file present there. Hence if you are running your code from any other directory either you would have to copy over this file or create a script in the startup folder. Hope this helps!!

How to make matlab see functions defined in .m files?

I'm a total newbie to MATLAB but I have to write some code in it. I've had problems with making MATLAB see functions I've defined in external .m files. This is what I've done: I've created a file named, say, foo.m in my home dir with the following contents:
function [y] = foo(x)
% description
y = x + 1
When I run matlab (my home dir is matlab's workdir) it does not see foo function - it replies with standard ??? Undefined function or variable 'foo' message. BUT help foo or which foo return correct data printing help text and pointing on foo.m file respectively.
I must be missing something but I have no idea what it is. This is getting very annoying.
Oh, after several trial and error attempts I've managed to call that function. Unfortunately I can't remember the sequence of steps I've performed. Moreover after restarting matlab it returns to its usual 'Undefined function or variable' response.
I have 7.11.0.584 matlab running on linux.
MATLAB needs to be told which directories to search over to access those m-files. Clearly it cannot be left to search over your entire disk drives. The MATLAB search path is a list of directories that will be searched in specific order to find your functions.
help addpath
help pathtool
You should never put those files anywhere in the official MATLAB toolbox directories. Choose an entirely separate directory.
Finally, be careful not to name your own functions to match the names of existing MATLAB functions. Otherwise, your very next question here will be why your code does not work properly. This is a common cause of strange and confusing bugs.
It seems you're having some trouble with addpath. Try opening the file in the matlab editor and adding a break point in the file. If the file is not on Matlab's path, matlab should ask if you want to change directory or add the file to the path, choose add to the path.
If this doesn't work, try changing the current working directory (displayed in the main window) to the same location as the m file and calling the function. If this doesn't work you're either getting the name wrong ar there's possibly something wrong with your installation.
Occasionally matlab has problems if it does not have write permission to the directory the file's in, so check that too, i.e. make sure admin rights aren't required for the directory or m file.
Oh, and try:
clear functions
to reload all functions into memory.
The function needs to be in MATLAB's path. Use pathtool to tell MATLAB where to find your function. Note that if you name a function the same name as an existing function, MATLAB will use whichever function it finds first according to the order that the paths are listed as you see them in pathtool.
Although coming late but I hope it will help someone.
If in the folder where the function you are calling is residing, there is any other function with the same name as one of the functions from MATLAB toolboxes, then Matlab will not recognize its license and therefore will disable the whole folder from execution, no matter it is properly added to the path. The help will display though.
In order to check it, type:
which name_of_func.m
and you will get the path with "%Has no license available" message.
If it is your own function, you should not get this message but only the path.
Therefore, find the function in this folder which has the same name as a MATLAB toolbox functions, and rename it. I will solve the problem :).
Best Regards
Wajahat

Matlab: how to find functions on path that use a given function

It sometimes happens that I need to change the behavior of a function. Is there an easy way to find functions (on the matlab path) that use that function?
The way I do this is to look for files that contain the name of the function I'm interested in. Thus, I don't only see who calls my function, but also what signature they use.
In the editor: Edit->Find Files
Start with help deprpt.
EDIT: when I run a dependency report there are 3 checkboxes at the top of the report window. One of these, by default unchecked, is called 'Show parent functions (current folder only)'. That is probably the beginning of what you want but it only works in a single folder.
If you want more than that, I suggest that you try edit deprpt.m.
I would use a tool like grep. I posted a tool called mgrep on the file exchange a few years ago. It can search through entire directories of m-files for any given string, and it searched recursively down into sub-directories. So to find functions in my directories that call fminsearch, I would merely execute this at the command line.
mgrep('fminsearch','.','show','off')
Searching directory(ies)...
/Users/woodchips/Desktop/My_FEX/cylinderfit.m
/Users/woodchips/Desktop/My_FEX/fminspleas.m
/Users/woodchips/Desktop/My_FEX/fminspleas2.m
/Users/woodchips/Desktop/My_FEX/fminspleas3.m
/Users/woodchips/Desktop/My_FEX/fminspleasnnls.m
/Users/woodchips/Desktop/My_FEX/BoundedFSOLVE/fsolvebnd.m
/Users/woodchips/Desktop/My_FEX/FMINSEARCHBND/fminsearchbnd.m
...
you mean like looking for dependencies? that would be tools -> show dependency report