Can I modify files with copyrighted by The Mathworks?

Some functions provided by MATLAB (genpath, for example) list a Copyright notice. Can I modify these to add capabilities and then resubmit them to the file exchange? If so, how should they be marked?

[Daniel Shub]

While I know the answer is No, I would love to hear solutions about what should be submitted to the FEX in these cases. In a number of cases I am using "patched" version of copyrighted functions. In a few cases the functions need to be directly overloaded (e.g., tex.m and subplot.m) while in most cases new file names are fine.

Answer 1

[Jan]

Some years ago, Matlab's filtfilt.m function could be accelerated massively by modifying some lines only. I did not submit the changed version to the FileExchange due to the copyright, but the function, which applied the modifications automatically. I asked TMW, if they agree with this solution.

Later on Matlab's original function has been improved also and I've removed this tool from the FEX.