<html>
<head>
<meta content="text/html; charset=UTF-8" http-equiv="Content-Type">
</head>
<body bgcolor="#FFFFFF" text="#000000">
<div class="moz-cite-prefix">On 25/6/2012 3:40 PM, Jed Brown wrote:<br>
</div>
<blockquote
cite="mid:CAM9tzS=S4aLcCRK1T4WLwyT+_8YFybyQ313LRf2Zgc1nRGeNCQ@mail.gmail.com"
type="cite">
<div class="gmail_quote">On Mon, Jun 25, 2012 at 12:25 PM, TAY
wee-beng <span dir="ltr"><<a moz-do-not-send="true"
href="mailto:zonexo@gmail.com" target="_blank">zonexo@gmail.com</a>></span>
wrote:<br>
<blockquote class="gmail_quote" style="margin:0 0 0
.8ex;border-left:1px #ccc solid;padding-left:1ex">
Hi,<br>
<br>
I'm trying to use DMDA to solve my linear equation.<br>
<br>
It works fine with 1 cpu. However, problem arise when cpu >
1. I get segmentation error.<br>
<br>
I tried to use MatView and PetscViewerASCIIOpen to view my
matrix to check if it's correct.<br>
<br>
It works with 1 cpu. However now, it shows the error below
when I use 2 cpu.<br>
<br>
[0]PETSC ERROR: --------------------- Error Message
------------------------------------<br>
[0]PETSC ERROR: Argument out of range!<br>
[0]PETSC ERROR: ASCII matrix output not allowed for matrices
with more than 1024 rows, use binary format instead.<br>
You can override this restriction using
-mat_ascii_output_large.!<br>
<br>
To view the matrix, my command is :<br>
<br>
call PetscViewerASCIIOpen(MPI_COMM_WORLD,"A_semi.txt",viewer,ierr)<br>
<br>
call MatView(A_semi,viewer,ierr)<br>
<br>
call PetscViewerDestroy(viewer,ierr)<br>
<br>
I tried to use -mat_ascii_output_large but then it just hangs
there forever.</blockquote>
<div><br>
</div>
<div>It may just be very slow.</div>
</div>
</blockquote>
<br>
I tried using 1 cpu and I got it in a few minutes. Should i take a
long time if I use 2 cpu? Also, I got the error:<br>
<br>
[0]PETSC ERROR: Argument out of range!<br>
[0]PETSC ERROR: ASCII matrix output not allowed for matrices with
more than 1024 rows, use binary format instead.<br>
<br>
It doesn't happen when I use 1 cpu. Is it normal to get it when I
use 2 cpu?<br>
<br>
I also tried to use :<br>
<br>
call MatView(A_semi,PETSC_VIEWER_STDOUT_WORLD ,ierr)<br>
<br>
but the same error occurs. It just hangs there when 2 cpu are used.<br>
<br>
<br>
<blockquote
cite="mid:CAM9tzS=S4aLcCRK1T4WLwyT+_8YFybyQ313LRf2Zgc1nRGeNCQ@mail.gmail.com"
type="cite">
<div class="gmail_quote">
<div><br>
</div>
<div>Why do you need ASCII? Writing anything large in ASCII is
hopeless. Please use binary.</div>
<div> </div>
<blockquote class="gmail_quote" style="margin:0 0 0
.8ex;border-left:1px #ccc solid;padding-left:1ex"> I create
the matrix using DMCreateMatrix. I don't have to use
MatCreateAIJ, right?<br>
<br>
Also, I check for the ierr value when I use
MatSetValuesStencil to ensure there's no error. Btw There's no
problem with VecView.<br>
<br>
So how can I view the matrix?<br>
<br>
Thank you!<span class="HOEnZb"><font color="#888888"><br>
<br>
-- <br>
Yours sincerely,<br>
<br>
TAY wee-beng<br>
<br>
</font></span></blockquote>
</div>
<br>
</blockquote>
<br>
<br>
</body>
</html>