SNESSetApplicationContext usage

[Vijay S. Mahadevan]

Matt,

> There is a misunderstanding. The application context is separate from both
> the Function context and the Jacobian context.

If the object completely belongs to the user, can I use this function to
pass on pointers to my user objects ? Or is there some advanced usage that
would conflict with this procedure ?

Alternately I did try using SetFunction/Jacobian() already followed by
SetFromOptions and it does pass the correct user context as expected. The
glitch in this path is that even when I have -snes_mf, my Jacobian function
is being called with a MFFD Mat type. And hence, I get an error there while
trying to manipulate it. I should note that the first time I use my SNES
object, the Jacobian is never called. It happens only after I set the
Jacobian again. 

Please do let me know if the first method or the second one would be a good
choice and the workaround needed to get it working. 

Thanks.
Vijay

> -----Original Message-----
> From: owner-petsc-users at mcs.anl.gov [mailto:owner-petsc-users at mcs.anl.gov]
> On Behalf Of Matthew Knepley
> Sent: Tuesday, March 25, 2008 9:16 PM
> To: petsc-users at mcs.anl.gov
> Subject: Re: SNESSetApplicationContext usage
> 
> On Tue, Mar 25, 2008 at 8:54 PM, Vijay S. Mahadevan <vijay.m at gmail.com>
> wrote:
> > Hi,
> >
> >  I am trying to use the SNESSetApplicationContext function to set an
> object
> >  as a user application context. This is being done after the SNESSolve
> was
> >  already called once on the SNES object, using a NULL application
> context.
> >
> >  For some reason, after the SNESSetApplicationContext call, the
> application
> >  context on SNES is not being set. I am wondering if maybe I need to set
> some
> >  flag to tell the SNES object to include this new context in further
> residual
> >  and Jacobian calls. I saw the code for the SNESSetApplicationContext
> >  function and it doesn't look like it but may be I am missing something
> ?
> 
> There is a misunderstanding. The application context is separate from both
> the
> Function context and the Jacobian context. If you want to change these,
> you
> must call SetFunction/Jacobian() again.
> 
>   Matt
> 
> >  Thanks for the help.
> >
> >  Vijay
> >
> >  No virus found in this outgoing message.
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> 3/25/2008
> >  10:26 AM
> >
> >
> >
> 
> 
> 
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> 
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> 

No virus found in this outgoing message.
Checked by AVG. 
Version: 7.5.519 / Virus Database: 269.22.0/1342 - Release Date: 3/25/2008
10:26 AM