Parallel Command in Octave

[J.D. Cole]

Hi all,
  I've currently been working on distributed support in Octave and have 
gotten some POC code working if anyone wants to check it out. Some of 
the main issues it addresses are:

1. High level command for simultaneous evaluation of scripts

For example:

----------- snip --------------
# A simple 2-D bandpass   

img = loadimage('default.img'); #Octave's built in baby face

kernel1 = ones (3)/9;
kernel2 = ones (5)/25;

parallel
parallelsection # this line is omittable
 result1 = conv2 (img, kernel1, 'same');
parallelsection
 result2 = conv2 (img, kernel2, 'same');
end

combine = result1 - result2;

imagesc (combine);
---------- snip -----------------

Each "parallelsection" is potentially executed on a remote node

2. Octave binary separation. One concern voiced in an earlier discussion 
of adding MPI support to Octave was that we didn't want people to have 
to recompile Octave if they wanted MPI support. I have added an 
interface layer in the Octave source which can be dynamically linked to 
what I call a PIL (Parallel Interface Library) to give MPI support (or 
your parallel interface of choice). If no PIL is specified at Octave 
startup, parallel command, such as the one shown above, are executed 
locally, in a serial fashion, yielding the same numerical results as if 
they were executed on multiple processors.

3. An Distributed Abstraction Layer. For those of you who have been 
following the discussions on implementing a better plotting commands in 
Octave, you'll know that everyone has a favorite package, but the 
general fealing is that Octave should have a uniform interface, with 
some capacity to access "special" features of individual packages. 
Distributed support is not much different: (1) Everyone has their 
favorite implementation MPI, PVM, etc ... (2) each one of those package 
have similarities and unique features. IMHO it would be wrong to tie 
Octave to one of these. The Parallel Interface Library potentially 
solves this problem by allowing users to implement an interface which 
allows Octave to execute the code shown above and/or additionally 
install implementation specific API's.

You can grab my current work here:

http://www.transientresearch.com/d-octave/

Don't worry, if you don't currently have a parallel setup, you can still 
play around with the parallel command stuff.

Can't wait to get some feedback.

--
J.D. Cole
Transient Research