petsc4py.typing.NNZSpec

petsc4py.typing.NNZSpec = int | typing.Sequence[int] | tuple[typing.Sequence[int], typing.Sequence[int]]

Nonzero pattern specification.

A single int corresponds to fixed number of non-zeros per row. A Sequence of int indicates different non-zeros per row. If a 2-tuple is used, the elements of the tuple corresponds to the on-process and off-process parts of the matrix.

See also

MatSeqAIJSetPreallocation, MatMPIAIJSetPreallocation