Method __init__

python/dolfinx/io/utils.py:46–97

Initialize a writer for outputting data in the VTX format. Args: comm: The MPI communicator filename: The output filename output: The data to output. Either a mesh, a single (discontinuous) Lagrange Function or list of

(
            self,
            comm: _MPI.Comm,
            filename: str | Path,
            output: Mesh | Function | list[Function] | tuple[Function],
            engine: str = "BPFile",
            mesh_policy: VTXMeshPolicy = VTXMeshPolicy.update,
        )

        _cpp_object: _cpp.io.VTXWriter_float32 | _cpp.io.VTXWriter_float64

        def __init__(
            self,
            comm: _MPI.Comm,
            filename: str | Path,
            output: Mesh | Function | list[Function] | tuple[Function],
            engine: str = "BPFile",
            mesh_policy: VTXMeshPolicy = VTXMeshPolicy.update,
        ):
            """Initialize a writer for outputting data in the VTX format.

            Args:
                comm: The MPI communicator
                filename: The output filename
                output: The data to output. Either a mesh, a single
                    (discontinuous) Lagrange Function or list of
                    (discontinuous) Lagrange Functions.
                engine: ADIOS2 engine to use for output. See
                    ADIOS2 documentation for options.
                mesh_policy: Controls if the mesh is written to file at
                    the first time step only when a ``Function`` is
                    written to file, or is re-written (updated) at each
                    time step. Has an effect only for ``Function``
                    output.

            Note:
                All Functions for output must share the same mesh and
                have the same element type.
            """
            # Get geometry type
            if isinstance(output, Mesh):
                dtype = output.geometry.x.dtype
            elif isinstance(output, Function):
                dtype = output.function_space.mesh.geometry.x.dtype
            else:
                dtype = output[0].function_space.mesh.geometry.x.dtype

            if np.issubdtype(dtype, np.float32):
                _vtxwriter = _cpp.io.VTXWriter_float32
            elif np.issubdtype(dtype, np.float64):
                _vtxwriter = _cpp.io.VTXWriter_float64
            else:
                raise RuntimeError(f"VTXWriter does not support dtype={dtype}.")

            if isinstance(output, Mesh):
                self._cpp_object = _vtxwriter(comm, filename, output._cpp_object, engine)  # type: ignore[union-attr]
            else:
                cpp_objects = (
                    [output._cpp_object]
                    if isinstance(output, Function)
                    else [o._cpp_object for o in output]
                )
                self._cpp_object = _vtxwriter(comm, filename, cpp_objects, engine, mesh_policy)

        def __enter__(self):
            """Enter context manager."""