PETSc sparsity

[Barry Smith]

  Toby,

   How are you applying boundary conditions? That requires the 
sparsity pattern? 

   Barry

As I said before in the parallel case there is no simple storage
of the sparsity pattern, we could provide it for you but it will take
additional memory.


On Sat, 16 Jun 2007, Toby Young wrote:

> 
> 
> 
> > I actually have a "bug" in Prometheus that makes me want the sparse
> > structure of whole system,
> 
> It would be very useful to have sparsity information at hand.
> 
> There are many ways to solve a system. My preferred way is (1) assemble
> system, (2) apply boundary conditions, and (3) solve. However to work in
> this way does often require good knowledge about how the matrix is set up;
> eg. what is the sparsity of the matrix.
> 
> How to implement it?
> 
> I appreceate your comments and discussion here.
> 
> Best,
> 	Toby
> 
> 
> -----
> 
> Toby D. Young (Adiunkt)
> Department of Computational Science
> Institute of Fundamental Technological Research
> Polish Academy of Science
> Room 206, ul. Swietokrzyska 21
> 00-049 Warszawa, POLAND
> 
> 
>