On Fri, 21 Nov 2008, Nathan Moore wrote:
Hi Joe,
I found the article you wrote for Linux Journal right about the time you
emailed last night - thanks for the reference and the suggestions! I find
that 1 beer and coding is ok, but num_beer .ge. 2 makes me too poetic and
insufficiently detail oriented. Debugging the next morning is never fun.
Nathan,
This is simply a matter of practice. Try coding with num_beer .ge. 10
for a few weeks, and then fall back to a lesser range. I'd say .ge. 12
but it is so difficult to get vomit out of a keyboard... it might take
you a while to build up enough new smooth endoplasmic reticula to be
able to cope with the really high ranges.
For a special treat, try balancing out the beer fuzz with cocaine or
methamphetamines. Much better than mere caffeine. One can type so
FAST, you know.
:-)
rgb
On Fri, Nov 21, 2008 at 9:23 AM, Joe Landman
<[EMAIL PROTECTED]> wrote:
Geoff Jacobs wrote:
If this were done with MPI, one would have to be
careful of the
boundaries on the matrix as it's partitioned for
computation. OpenMP is
intelligent enough to hold off computation on the
tiles south and east
of the first until the first is done, and so forth?
No... I didn't address the interior vs exterior. I have a nice worked
example where I convert this sort of code into an exterior, a skin,
and the communication for an MPI and OpenMP version. Scales pretty
well. You are right, I should have fixed that as well.
! now all you need is a "linear scan" to find
positive elements in
! dv. You can approach these as sum
reductions, and do them in
! parallel
do i=1,Nx
sum=0.0
do j=1,Ny
sum = sum + dabs(dv(i,j) .gt. 0.0) * dv(i,j)
end do
if (sum .gt. 0.0) converged = 0
end do
The basic idea is to replace the inner loop
conditionals and remove as
many of the shared variables as possible.
Yup, keep things pipelined.
That was the idea, though I didn't compile/test the code to be sure it
would work. That and I usually try to avoid real coding when I am
tired at night. Coding and beer don't mix (for me).
--
Joseph Landman, Ph.D
Founder and CEO
Scalable Informatics LLC,
email: [EMAIL PROTECTED]
web : http://www.scalableinformatics.com
http://jackrabbit.scalableinformatics.com
phone: +1 734 786 8423 x121
fax : +1 866 888 3112
cell : +1 734 612 4615
--
- - - - - - - - - - - - - - - - - - - - -
Nathan Moore
Assistant Professor, Physics
Winona State University
AIM: nmoorewsu
- - - - - - - - - - - - - - - - - - - - -
Robert G. Brown Phone(cell): 1-919-280-8443
Duke University Physics Dept, Box 90305
Durham, N.C. 27708-0305
Web: http://www.phy.duke.edu/~rgb
Book of Lilith Website: http://www.phy.duke.edu/~rgb/Lilith/Lilith.php
Lulu Bookstore: http://stores.lulu.com/store.php?fAcctID=877977
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