Rectified Gaussian Belief Networks

Software for Matlab 4.2

Copyright © 1997
Zoubin Ghahramani
Dept of Computer Science
University of Toronto

Released July 28, 1997

This software implements the unsupervised learning algorithm described in the following paper:
1. Downloading and uncompressing
2. Getting started
3. MEX files
4. Compatibility
5. Support

  • 1. Downloading and uncompressing

    On UNIX:

    1. ftp the software
    2. gzip -d rgbn.tar.gz
    3. tar xvf rgbn.tar

    This should create a directory called rgbn with all the necessary files in there.

  • 2. Getting started

    Start up Matlab (4.2).
    At the Matlab prompt:

    >> trystereo

    runs the stereo (shifter) problem. It should display the weights during learning every 400 iterations. How long this takes depends on whether you are using MEX files or not, and how fast your machine is. On our machine (SGI R4400 processors) using MEX files it takes about 1 min.

    >> trybars

    runs the bars problem. It should display weights after 200 iterations (about 30 secs on our machine).

    If you want to understand the code, you can look at trystereo.m which has many comments and refer to the paper.

  • 3. MEX files

    The code will run about 10 times faster if you use the Matlab executable files (*.mex). I have provided precompiled versions for Solaris and SGI IRIS 4D platforms. On other platforms I strongly recommend that you try to compile the source code I've provided. This should be easy (look at the Makefile). For example, on SUN 4 platforms, type at the UNIX prompt:

    make all4

  • 4. Compatibility

    This code should work on any Matlab 4.2 platform. I've also tried it on Matlab 5 and it ran, although unless the ".mex" files are ported, it will resort to the ".m" files. I think the port is very easy, but I have not had a chance to do it yet.

  • 5. Support

    You're on your own.

    Actually, if you have a bug report or are really stuck understanding something, send me an email at and I will try to respond.

  • Copyright © 1997 by Zoubin Ghahramani
    Toronto, Ontario, Canada
    All Rights Reserved

    Permission to use, copy, modify, and distribute this software and its documentation for non-commercial purposes only is hereby granted without fee, provided that the above copyright notice appears in all copies and that both the copyright notice and this permission notice appear in supporting documentation, and that my name not be used in advertising or publicity pertaining to distribution of the software without specific, written prior permission. I make no representations about the suitability of this software for any purpose. It is provided "as is" without express or implied warranty.

    I disclaim all warranties with regard to this software, including all implied warranties of merchantability and fitness. In no event shall I be liable for any special, indirect or consequential damages or any damages whatsoever resulting from loss of use, data or profits, whether in an action of contract, negligence or other tortious action, arising out of or in connection with the use or performance of this software.