On Fri, Feb 10, 2012 at 7:57 PM, Jed Brown <jedbrown at mcs.anl.gov> wrote:
> On Fri, Feb 10, 2012 at 19:51, Dmitry Karpeev <karpeev at mcs.anl.gov> wrote: > >> How does this explanation square with the following code from KSPSetUp? >> >> if (ksp->dmActive && !ksp->setupstage) { >> /* first time in so build matrix and vector data structures using DM >> */ >> if (!ksp->vec_rhs) {ierr = >> DMCreateGlobalVector(ksp->dm,&ksp->vec_rhs);CHKERRQ(ierr);} >> if (!ksp->vec_sol) {ierr = >> DMCreateGlobalVector(ksp->dm,&ksp->vec_sol);CHKERRQ(ierr);} >> ierr = DMCreateMatrix(ksp->dm,MATAIJ,&A);CHKERRQ(ierr); >> ierr = KSPSetOperators(ksp,A,A,stflg);CHKERRQ(ierr); >> ierr = PetscObjectDereference((PetscObject)A);CHKERRQ(ierr); >> } >> > > Look down the page a little, DMComputeJacobian() is what actually > assembles. > > if (ksp->setupstage != KSP_SETUP_NEWRHS) { > ierr = KSPGetOperators(ksp,&A,&A,PETSC_NULL);CHKERRQ(ierr); > ierr = > DMComputeJacobian(ksp->dm,PETSC_NULL,A,A,&stflg);CHKERRQ(ierr); > ierr = KSPSetOperators(ksp,A,A,stflg);CHKERRQ(ierr); > } > > Okay. Then what's the need for DMSetPreallocateOnly()? Dmitry. -------------- next part -------------- An HTML attachment was scrubbed... URL: <http://lists.mcs.anl.gov/pipermail/petsc-dev/attachments/20120210/05d397cf/attachment.html>