[petsc-dev] Lagging the numerical factorization for one of the fields of fieldsplit preconditioner

[Barry Smith]

On Mar 15, 2011, at 6:33 PM, Jed Brown wrote:

> On Wed, Mar 16, 2011 at 00:29, Barry Smith <bsmith at mcs.anl.gov> wrote:
> Of course I know what A is. Because I am only doing this tracking after a MatGetSubmatrix() has been called which provide the information about what A is.
> 
> Yes, that's much better and another reason for MatGetSubMatrix() to retain ownership of the submatrices.

  When you "retain ownership" you could also do things like zero the setvalues() pointer etc to prevent the user from changing it?

  Barry