Can I force visdiff to display more than the first 2000 bytes?

Question

I have two binary files that I'm trying to compare using Matlab's built-in function visdiff, but it only displays the first 2000 bytes as a default. Is there any way to force the comparison tool to display the entire contents of both files side by side?

Answer 1

Edit the file matlabroot\toolbox\shared\comparisons\private\bindiff.m, where matlabroot is your MATLAB installation directory. On line 149, you'll see it sets the variable MAXLEN to 2000. Change this to something bigger (even Inf seems to work).

You may need to type rehash toolboxcache after making this change, in order to get MATLAB to notice.

Please note:

1. As you're making a change to the MATLAB source, this is at your own risk (it seems fine to me though). Keep a backup of the file you've edited.
2. That truncation at 2000 bytes is there for a reason - comparing the whole of larger binary files does seem to take quite a while, so be patient. Maybe try gradually increasing MAXLEN, rather than going straight to Inf.
3. I only have R2011b available to me right now, so if you're on a newer version the file path and line number I mentioned above may have changed. It was very easy to trace through the code from visdiff to comparisons_private to bindiff though, so unless they've changed the deeper structure of the Comparisons Tool between 11b and now, it will probably be very similar.