Method sub

python/dolfinx/fem/function.py:584–601

Return a sub-function (a view into the ``Function``). Sub-functions are indexed ``i = 0, ..., N-1``, where ``N`` is the number of sub-spaces. Args: i: Index of the sub-function to extract. Returns: A view into the parent ``Function``.

(self, i: int)

        return self.name

    def sub(self, i: int) -> Function[Scalar]:
        """Return a sub-function (a view into the ``Function``).

        Sub-functions are indexed ``i = 0, ..., N-1``, where ``N`` is
        the number of sub-spaces.

        Args:
            i: Index of the sub-function to extract.

        Returns:
            A view into the parent ``Function``.

        Note:
            If the sub-Function is re-used, for performance reasons the
            returned ``Function`` should be stored by the caller to
            avoid repeated re-computation of the subspace.
        """
        return Function(self._V.sub(i), self.x, name=f"{self!s}_{i}")

    def split(self) -> tuple[Function[Scalar], ...]:
        """Extract (any) sub-functions.