This looks like one block row per process? (BAIJ formats store explicit zeros that appear within nonzero blocks.) You'd use d_nnz[] = {1}, o_nnz[] = {1} on each process.
If each of the dummy numbers there was replaced by a nonzero block (so the diagram would be sketching nonzero 3x3 blocks of an 18x18 matrix), then you'd have bs=3 with: rank 0: d_nnz[] = {2,2,1}, o_nnz[] = {1,1,2}; rank 1: d_nnz[] = {1,1,1}, o_nnz[] = {2,1,1}; Edoardo alinovi <edoardo.alin...@gmail.com> writes: > Thank you Jed for the hint. > > So just to understand it with an example. Say I have this matrix here, > which has 4 3x3 blocks > > 1 2 0 | 0 5 0 | > 0 2 3 | 0 0 1 | <---- Proc 1 > 0 0 1 | 0 2 2 | > --------|--------| > 1 2 0 | 0 5 0 | > 0 2 0 | 0 0 1 | <---- Proc 2 > 0 0 1 | 0 0 2 | > -------|---------| > > This can be represented as a collection of submatrices like: > A B > C D > > A and D are the diagonal blocks, while B and C are the off-diagonal ones. > How should I set d_nnz and o_nnz in this case?