[petsc-dev] PETSC application

[David sheehan]

>First, configure with Hypre .
You mean, configure for the installation of PETSC with hypre? thanks.

>Then -pc_type hypre -pc_hypre_type boomeramg
You mean, without adding any information into code include, just compile and
link
the code, to get an excuteable file, e.g. "a.out", then
a.out -pc_type hypre -pc_hypre_type boomeramg
is it right? thanks.

>I cannot understand exactly what you mean. However, if you want to create a
PC
> based upon a >matrix which is not the system matrix A, you can specify it
in
> KSPSetOperators().

I mean Ax =b doesn't have A in explicit form, but in expression
A=B+C1+C2+...+Cn,
where B is main part of A in an explicity form, C1, C2,... and Cn are small
portions
comparing with B and they don't have an explicit form. Thus I want  to  make
a
preconditioner from B, then apply the preconditioner to Ax=b. Please tell me
how I
can do by PETSC sentences for PETSC solver, thanks.


David


On Sun, Mar 7, 2010 at 12:32 AM, Matthew Knepley <knepley at gmail.com> wrote:

> On Sat, Mar 6, 2010 at 11:49 PM, David sheehan <david.sheehanjr at gmail.com>wrote:
>
>> Hi,
>> I need your helps about PETSC as follows:
>> 1) how can I call boomerAMG of HYPRE through PETSC as a solver and a
>> preconditioner?
>>
>
> First, configure with Hypre . Then -pc_type hypre -pc_hypre_type boomeramg
>
>
>> 2) how can I make a precondioner  from B matrix,  but apply the
>> preconditioner to Ax=b in PETSC?
>> Thanks in advance.
>>
>
> I cannot understand exactly what you mean. However, if you want to create a
> PC based upon a matrix
> which is not the system matrix A, you can specify it in KSPSetOperators().
>
>   Matt
>
>
>> David
>>
> --
> 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
>
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.mcs.anl.gov/pipermail/petsc-dev/attachments/20100307/378213f4/attachment.html>