Hi David,
> One interesting thing that I didn't realize for a long time is that PETSc > condenses the sparsity pattern when you call matrix->close(), i.e.: > > http://www.mcs.anl.gov/petsc/petsc-current/docs/manualpages/Mat/MatAssemblyBegin.html > "Space for preallocated nonzeros that is not filled by a call to > MatSetValues() or a related routine are compressed out by assembly. If you > intend to use that extra space on a subsequent assembly, be sure to insert > explicit zeros before MAT_FINAL_ASSEMBLY so the space is not compressed > out." > So in this case, if you're using PETSc/SLEPc, then B will be diagonal > after the matrix is "closed". > Interesting! Thanks for the info. At the moment, I'm adding a dense matrix of the phi overlaps to B for each element. So this will be basically placing off-diagonal zeros in the B PETSc matrix. I just need to add the diagonals to make the sparsity pattern diagonal during assembly. Harshad ------------------------------------------------------------------------------ Site24x7 APM Insight: Get Deep Visibility into Application Performance APM + Mobile APM + RUM: Monitor 3 App instances at just $35/Month Monitor end-to-end web transactions and take corrective actions now Troubleshoot faster and improve end-user experience. Signup Now! http://pubads.g.doubleclick.net/gampad/clk?id=272487151&iu=/4140 _______________________________________________ Libmesh-users mailing list Libmesh-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/libmesh-users
