On Mon, 2008-08-04 at 23:13 +0800, Zi-Hao Wei wrote: > On Mon, Aug 4, 2008 at 10:53 PM, Ahmed El Zein <ahmed at azein.com> wrote: > > my code looks like: > > ierr = MatCreate(PETSC_COMM_WORLD,&A); CHKERRQ(ierr); > > ierr = MatSetSizes(A,M,N,M,N); CHKERRQ(ierr); > > ierr = MatSetType(A, MATSEQAIJ); CHKERRQ(ierr); > > ierr = MatAssemblyBegin(A, MAT_FINAL_ASSEMBLY); CHKERRQ(ierr); > > [...lots of MatSetValue() calls...] > > ierr = MatAssemblyEnd(A, MAT_FINAL_ASSEMBLY); CHKERRQ(ierr); > > I think that the code should be > ierr = MatCreate(PETSC_COMM_WORLD,&A); CHKERRQ(ierr); > ierr = MatSetSizes(A,M,N,M,N); CHKERRQ(ierr); > ierr = MatSetType(A, MATSEQAIJ); CHKERRQ(ierr); > [...lots of MatSetValue() calls...] > ierr = MatAssemblyBegin(A, MAT_FINAL_ASSEMBLY); CHKERRQ(ierr); > ierr = MatAssemblyEnd(A, MAT_FINAL_ASSEMBLY); CHKERRQ(ierr); > > The routines MatAssemblyBegin and MatAssemblyEnd should be called > after completing all calls to MatSetValues(). You are right of course. But if these 2 calls are meant to be right after each other, why isn't there just one MatAssembly() call versus a Begin and End call?
btw fixing this did not affect the problem I had. Ahmed
