Discover MakerZone

MATLAB and Simulink resources for Arduino, LEGO, and Raspberry Pi

Learn more

Discover what MATLAB® can do for your career.

Opportunities for recent engineering grads.

Apply Today

License files from the FEX

Asked by Jan Simon on 18 Jun 2012

FEX submissions are accompanied by a file called "license.txt", which contains the name of the author. You can copy the files of a submission to a specific folder and include if in the Matlab path.

When a user downloads 100 submissions, there are two methods:

  • Either 100 folders are added to the path. This increases the danger of getting the strange and frequent "exhausted change notification handles" problems, see Solution 1-18IFI.
  • Save the functions to one folder and overwrite the license files. This does collide with the BSD license conditions.

Especially when I think about a tool, which automatically resolves dependencies to other FEX submissions, the pile of equivocal license files is a tedious obstacle. How can this problem be solved considering the large number of already existing submissions?


Jan Simon


No products are associated with this question.

3 Answers

Answer by Daniel on 19 Jun 2012
Accepted answer

You could download each FEX submission to a separate folder and then create links (hard or symbolic) to the MATLAB files (m, p, mex, etc.) in a single common folder for all FEX submissions. This might cause problems with name collisions to common files (e.g., contents.m).

1 Comment

Jan Simon on 20 Jun 2012

The links are a good idea. The contents.m file is no problem here, because it should be re-created dynamically and contain the names of all functions contained inside a folder.

One problem is, that some submissions *require* specific subfolders, such that adding the folder to the PATH is obligatory. Therefore a full automatic package mamagement is not possible currently. However, the usability of the FEX is *decreasing* with a growing number of submissions, as long as there is no management function which resolves the depenencies.

Answer by Malcolm Lidierth on 22 May 2013


I find lots of "installation procedure" enquiries also even though clear install instructions are provided. Often that is because users have read "between-the-lines" instead of taking the instructions literally - and their interpretation can be understandable e.g I see how a 10 year old caveat that "you must use "save -v6" might be interpreted as use "save -v[6 or 7]" in 2013.

For Waterloo, which has many files/folders/classes, I wrote a short script that uses MATLAB to do the download, unzip the files and set up the MATLAB and Java path - providing a few command line prompts/questions - in the present context that might be e.g "Have you run mex -setup before? If not do you want to run it now? [y/N]:"

Maybe the FEX should include an o[tional "Installation Script" button as well as a "Download Button" - providing script code to cut-and-paste into the Command Window when clicked, that could do this.

1 Comment

Jan Simon on 22 May 2013

Thanks for your answer, Malcolm. In modern matlab versions the mex() command can reply, if the setup has been performed already. Unfortunately you cannot rely on FEX users to run a modern matlab version.

The install mechanism for Waterloo is fine for 99% of the cases. I do not have an internet connection on my Matlab computer to secure the stored patient data. Then an automatic downloading must fail, but it is impossible to guarantee a comfortable and flexible solution for all setups.

Malcolm Lidierth
Answer by Jan Simon on 20 Jun 2012

The license.txt files could be renamed by appending the name of the submission, e.g. "licence.txt" to "license_typecast_.txt" for James' important, efficient and useful helper function FEX: 17476.

A lot of users are overwhelmed by the installation procedures of some submissions. I include a "please compile the code by mex -O abc.c before the first run" in the help section of the code, but I still get more questions for clarifications about the MEX command than comments or ratings. Therefore I hesitate to force the user to download and install another function and compile it in addition.


Jan Simon

Contact us