PCGetFactoredMatrix

[John R. Wicks]

I would like to compute the residual A - LU, where LU is the ILU
factorization of A.  What is the most convenient way of doing so?

> -----Original Message-----
> From: owner-petsc-users at mcs.anl.gov 
> [mailto:owner-petsc-users at mcs.anl.gov] On Behalf Of Matthew Knepley
> Sent: Thursday, November 29, 2007 12:04 PM
> To: petsc-users at mcs.anl.gov
> Subject: Re: PCGetFactoredMatrix
> 
> 
> It depends on the package, but the petsc stuff stores L and U 
> in one matrix.
> 
>    Matt
> 
> On Nov 29, 2007 9:03 AM, John R. Wicks <jwicks at cs.brown.edu> wrote:
> > The documentation for PCGetFactoredMatrix is not clear.  What does 
> > this return for ILU(0), for example? Does it return the 
> product LU or 
> > the in place factorization?
> >
> >
> 
> 
> 
> -- 
> 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
>