On Thu, Jun 16, 2011 at 17:34, Matthew Knepley <knepley at gmail.com> wrote:
> Yes, you can do MF applications of A' A. You could just make a MatShell > that called MatMult and MatMultTranspose. > MatShell is not necessary, just use MatCreateTranspose(). http://www.mcs.anl.gov/petsc/petsc-as/snapshots/petsc-dev/docs/manualpages/Mat/MatCreateTranspose.html But I think Alexander is clear on that part. > For modifying the matrix, MatGetRow() IF you are using an AIJ matrix, > return a pointer directly to the values. > This is only for SeqAIJ. Alexander, could you clarify where in the Gauss-Newton procedure you outlined is the dense matrix on which you need to do the nonlinear row operation? Also, the matrix A'*A has a huge null space. What sort of regularization are you using. -------------- next part -------------- An HTML attachment was scrubbed... URL: <http://lists.mcs.anl.gov/pipermail/petsc-users/attachments/20110616/9c5bc937/attachment.htm>
