Klaus Burkart <k_burk...@yahoo.com> writes:
> How can I preallocate space for matrices (some symmetric, others
> asymmetric) if I have the global number of nonzeros (NNZ) but not the
> number of nonzeros per row?
Unfortunately, this is not enough for efficient assembly. It is more
efficient to over-estimate.
> I could compute the NNZ for the upper or lower part separately if this
> would be useful for symmetric matrices.
> I create the matrix this way:
> MatCreate(PETSC_COMM_WORLD, &M);
> MatSetSizes(M, PETSC_DECIDE, PETSC_DECIDE, N, N);