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Re: Nonzeros of SBAIJ

To: petsc-users@xxxxxxxxxxx
Subject: Re: Nonzeros of SBAIJ
From: Hong Zhang <hzhang@xxxxxxxxxxx>
Date: Wed, 14 Nov 2007 10:17:28 -0600 (CST)
In-reply-to: <473B1D8B.30900@ewi.tudelft.nl>
References: <47388126.2010607@ewi.tudelft.nl> <Pine.LNX.4.64.0711121115040.28623@terra.mcs.anl.gov> <64C31677-0447-46D7-9F6D-8EB59777E7BE@mcs.anl.gov> <473B1D8B.30900@ewi.tudelft.nl>
Reply-to: petsc-users@xxxxxxxxxxx
Sender: owner-petsc-users@xxxxxxxxxxx

Dear all
I allocated the memory exactly with symbolic computation, and tried preallocation on AIJ and SBAIJ, it works well for AIJ, no additional allocaiton is needed in assembly... then I did it on SBAIJ ( nonzeros of upper triangular part + 1), the performance is much worse , it seems that memory allocation was still needed... does anyone have such problem before?


May I have the segment of your code that implements the memory allocation?
I'll test it and see what is the problem.

BTW, you may send this type of request to petsc-maint@xxxxxxxxxxx
instead of petsc-users.

Hong


Thank you
Best regards
Zhifeng Sheng

References:
- Nonzeros of SBAIJ
  - From: Zhifeng Sheng
- Re: Nonzeros of SBAIJ
  - From: Hong Zhang
- Re: Nonzeros of SBAIJ
  - From: Barry Smith
- Re: Nonzeros of SBAIJ
  - From: Zhifeng Sheng

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