Function assemble_matrix

python/dolfinx/fem/assemble.py:257–293

Assemble bilinear form into a matrix. Args: a: The bilinear form assemble. bcs: Boundary conditions that affect the assembled matrix. Degrees-of-freedom constrained by a boundary condition will have their rows/columns zeroed and the value ``diagonal``

(
    a: typing.Any,
    bcs: Sequence[DirichletBC] | None = None,
    diag: float = 1.0,
    constants: npt.NDArray | None = None,
    coeffs: dict[tuple[IntegralType, int], npt.NDArray] | None = None,
    block_mode: la.BlockMode | None = None,
)

@functools.singledispatch
def assemble_matrix(
    a: typing.Any,
    bcs: Sequence[DirichletBC] | None = None,
    diag: float = 1.0,
    constants: npt.NDArray | None = None,
    coeffs: dict[tuple[IntegralType, int], npt.NDArray] | None = None,
    block_mode: la.BlockMode | None = None,
) -> la.MatrixCSR:
    """Assemble bilinear form into a matrix.

    Args:
        a: The bilinear form assemble.
        bcs: Boundary conditions that affect the assembled matrix.
            Degrees-of-freedom constrained by a boundary condition will
            have their rows/columns zeroed and the value ``diagonal``
            set on on the matrix diagonal.
        diag: Value to set on the matrix diagonal for Dirichlet
            boundary condition constrained degrees-of-freedom belonging
            to the same trial and test space.
        constants: Constants that appear in the form. If ``None``,
            any required constants will be computed.
        coeffs: Coefficients that appear in the form. If not provided,
            any required coefficients will be computed.
        block_mode: Block size mode for the returned space matrix. If
            ``None``, default is used.

    Returns:
        Matrix representation of the bilinear form ``a``.

    Note:
        The returned matrix is not finalised, i.e. ghost values are not
        accumulated.
    """
    bcs = [] if bcs is None else bcs
    A: la.MatrixCSR = create_matrix(a, block_mode)
    _assemble_matrix_csr(A, a, bcs, diag, constants, coeffs)
    return A


@assemble_matrix.register