|  | slice | - the DM object | 
|  | d_nz | - number of block nonzeros per block row in diagonal portion of local
submatrix  (same for all local rows) | 
|  | d_nnz | - array containing the number of block nonzeros in the various block rows
of the in diagonal portion of the local (possibly different for each block
row) or NULL. | 
|  | o_nz | - number of block nonzeros per block row in the off-diagonal portion of local
submatrix (same for all local rows). | 
|  | o_nnz | - array containing the number of nonzeros in the various block rows of the
off-diagonal portion of the local submatrix (possibly different for
each block row) or NULL. |