On Wed, Feb 11, 2009 at 1:46 PM, Yixun Liu <enjoywm at cs.wm.edu> wrote:
> Hi, > In ksp/ex2.c > > /* > Set operators. Here the matrix that defines the linear system > also serves as the preconditioning matrix. > */ > ierr = KSPSetOperators(ksp,A,A,DIFFERENT_NONZERO_PATTERN);CHKERRQ(ierr); > > The matrix related with linear system is same with the preconditioning > matrix, why set the flat to be DIFFERENT_NONZERO_PATTERN? This flag has to do with whether the PC is reformed. There is a section in the manual on this. Matt > > Thanks. > -- 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 -------------- next part -------------- An HTML attachment was scrubbed... URL: <http://lists.mcs.anl.gov/pipermail/petsc-users/attachments/20090211/c65af6ce/attachment.htm>
