[Foxtrot] Re: (group project foxtrot) MPQS matrix reduction in parallel (fwd)

[Michael Pinna]

Here's the reply... As I suspected he's telling us not to bother with the
interesting solution.

Mike

-- 
"...like the liberated debater toasting the bowl."
      --Anon

---------- Forwarded message ----------
Date: Sat, 10 Feb 2001 16:06:38 +0000
From: Ross Anderson <Ross.Anderson@cl.cam.ac.uk>
To: Michael Pinna <map36@cam.ac.uk>
Cc: ross.anderson@cl.cam.ac.uk, Ross.Anderson@cl.cam.ac.uk
Subject: Re: (group project foxtrot) MPQS matrix reduction in parallel 

For the size of problem you're likely to be working with, you
should just accept that the matrix reduction will be done on
one machine, even if it limits the size of the number you can
factor to a hundred digits or so.

There are ways of distributing the matrix reduction, but they
are still in the category of `rocket science' rather than
undergraduate project material. The world expert on them is
Paul Leyland at Microsoft Research across the road; by all
means talk to him if you wish, but I expect he will discourage
you from trying to implement complex and poorly-understood
algorithms (block Lanczos) in a time-limited project. Even if
you decide to `have a go', for goodness' sake leave it as an
optional extra that you can tackle once you have a project
that otherwise works and will get you your ticks,

Ross Anderson