space allocation for a parallel matrix

[Matthew Knepley]

On Tue, Feb 3, 2009 at 9:56 AM, Yixun Liu <enjoywm at cs.wm.edu> wrote:
> It means that it is better to set n to be equal to the column to avoid
> the communication. Right? If it does, I am confusing why we need this
> parameter. Just for dealing with very large vector x?
> Thanks.!

No. Please take a look at the book I recommended. If you do as you suggest,
this is no longer parallel computing.

  Matt

-- 
What most experimenters take for granted before they begin their
experiments is infinitely more interesting than any results to which
their experiments lead.
-- Norbert Wiener