On Mon, Jun 20, 2011 at 9:31 PM, Mohammad Mirzadeh <mirzadeh at gmail.com>wrote:
> Thanks John -- taht's helpful. Do you also know how I can change the > tolerance for dropping elements? > Right now, this only discards entires which are exactly floating point 0.0. Matt > Mohammad > > On Mon, Jun 20, 2011 at 1:12 PM, John Mousel <john.mousel at gmail.com>wrote: > >> See the matrix options available in the man pages. I think the function >> below is what you are looking for. >> >> >> http://www.mcs.anl.gov/petsc/petsc-as/snapshots/petsc-current/docs/manualpages/Mat/MatSetOption.html >> >> >> MatSetOption >> <http://www.mcs.anl.gov/petsc/petsc-as/snapshots/petsc-current/docs/manualpages/Mat/MatSetOption.html#MatSetOption>(A,MAT_IGNORE_ZERO_ENTRIES,PETSC_TRUE >> >> <http://www.mcs.anl.gov/petsc/petsc-as/snapshots/petsc-current/docs/manualpages/Sys/PETSC_TRUE.html#PETSC_TRUE>); >> >> >> >> >> Best Regards, >> John >> >> >> >> >> On Mon, Jun 20, 2011 at 2:42 PM, Mohammad Mirzadeh <mirzadeh at >> gmail.com>wrote: >> >>> Hi folks, >>> >>> I've noticed that MatSetValues explicitly inserts zeros in the matrix if >>> an element is really zero. Is there a way to drop elements (or not save them >>> in the first place) that are below a certain tolerance? I realize one way of >>> doing it is in the application code and when using MatSetValues but I'm just >>> wondering if PETSc has a function for it? >>> >>> Thanks, >>> Mohammad >>> >> >> > -- 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/20110620/0a470699/attachment.htm>
