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[Scalapack] Some questions about Scalapack.

Dear Sir, 

I am working one project which needs the subroutine `PDGBTRF' and 'PDGBTRS' 
from Scalapack.  So far, I have one problem that I could not fix for a while. I 
almost tried all the way I can, but it seems no one works. :(

Let N be the order of the global matrix A, and NB?as the block size on each 
process.   I find the attached code works very well in the following cases:
1) NB?= N/Process_number; or 2). A is a tridiagonal?matrix, i.e. BWL?= BWU?= 1;

However, when none of the above is satisfied (for example, BWL?= BWU?= 2, N = 
9, Process_number = 2, and NB?= 1+BWU+BWL?= 5), I could not get the 
LU?decomposition properly. The return information is always 'INFO = 7'.  In 
fact, I am not sure if I distribute the matrix correctly. 

Could you please take a look at the attached small code, which I show how I 
distribute the matrix? Any advice will be appreciated.  Thank you sssooo?much 
for your time and help in advance. 

I am looking forward to your reply.

Best Regards!

Yanzhi




------------------------------------------------------------------------------- 
Yanzhi?Zhang
Postdoctoral Research Associate
Department of Scientific Computing
Florida State University
493 Dirac Science Library
Tallahassee, FL 32306-4120 
Phone:  1-850-644-7057
Email:   yzhang5@Domain.Removed
URL: http://people.scs.fsu.edu/~yzhang
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