spectral_galerkin_heat.io_utils.xdmf_io

XDMF file loading and writing utilities.

Provides functions to read simulation results from XDMF/HDF5 format and write error fields for visualization in ParaView.

Uses xml.etree.ElementTree for proper XML generation instead of hardcoded string templates.

Classes

`StructuredField`	Temperature on a rectilinear (3DRectMesh / VXVYVZ) grid.
`UnstructuredField`	Temperature at scattered FE nodes (Tetrahedron / XYZ).
`XdmfBuilder`	Build XDMF XML documents for structured (3DRectMesh) and

Functions

`load_xdmf`(xdmf_path[, attr_name])	Load the last time step from an XDMF file.
`write_structured_fields`(output_base, fields, x, y, z)	Write multiple structured fields to HDF5 + XDMF.
`write_unstructured_fields`(output_base, fields, xyz, ...)	Write multiple fields on an unstructured (tetrahedral) mesh to HDF5 + XDMF.

Module Contents

class spectral_galerkin_heat.io_utils.xdmf_io.StructuredField: Temperature on a rectilinear (3DRectMesh / VXVYVZ) grid.

class spectral_galerkin_heat.io_utils.xdmf_io.UnstructuredField: Temperature at scattered FE nodes (Tetrahedron / XYZ).

class spectral_galerkin_heat.io_utils.xdmf_io.XdmfBuilder(version='2.0')

Build XDMF XML documents for structured (3DRectMesh) and unstructured (Tetrahedron) grids, via xml.etree.ElementTree.

Parameters:: version (str)

add_structured_grid(name, dims, h5_ref, coord_datasets=('X', 'Y', 'Z'), attributes=None, time=None, step=None, precision=4, parent=None)

Add a structured 3DRectMesh grid to the XDMF document.

Parameters:

name (str) – Name of the grid (e.g., “Error”, “Mesh”)
dims (tuple of int) – Grid dimensions in (nz, ny, nx) order
h5_ref (str) – HDF5 filename reference (basename only)
coord_datasets (tuple of str) – Dataset names for X, Y, Z coordinates in HDF5
attributes (dict, optional) – Mapping of attribute names to HDF5 dataset names
time (float, optional) – Time value for this grid
step (int, optional) – Step number for this grid
precision (int) – Float precision (4 for float32, 8 for float64)
parent (xml.etree.ElementTree.Element | None)

Returns:

The created Grid element

Return type:

ET.Element

add_unstructured_grid(name, n_vertices, n_elements, h5_ref, topology_dataset='topology', geometry_dataset='geometry', topology_type='Tetrahedron', nodes_per_element=4, attributes=None, time=None, geometry_precision=8, attribute_precision=4)

Add an unstructured grid to the XDMF document.

Parameters:

name (str) – Name of the grid
n_vertices (int) – Number of vertices in the mesh
n_elements (int) – Number of elements (e.g., tetrahedra)
h5_ref (str) – HDF5 filename reference (basename only)
topology_dataset (str) – HDF5 dataset name for connectivity
geometry_dataset (str) – HDF5 dataset name for vertex coordinates
topology_type (str) – Element type (e.g., “Tetrahedron”, “Triangle”)
nodes_per_element (int) – Nodes per element (e.g., 4 for tetrahedra)
attributes (dict, optional) – Mapping of attribute names to HDF5 dataset names
time (float, optional) – Time value for this grid
geometry_precision (int) – Float precision for geometry (default 8 = float64)
attribute_precision (int) – Float precision for attributes (default 4 = float32)

Returns:

The created Grid element

Return type:

ET.Element

to_string(indent=True)

Convert the XDMF document to a string.

Parameters:: indent (bool) – Whether to pretty-print with indentation
Returns:: The XDMF XML document as a string
Return type:: str

write(filepath)

Write the XDMF document to a file.

Parameters:: filepath (Path) – Path to the output file
Return type:: None

spectral_galerkin_heat.io_utils.xdmf_io.load_xdmf(xdmf_path, attr_name=None)

Load the last time step from an XDMF file.

Parameters:

xdmf_path (Path) – Path to the .xdmf or .xmf file.
attr_name (str or None) – Name of the Attribute to load (e.g. "temperature"). If None, the first <Attribute> element found is used. Also used to select among multiple temporal collections.

Return type:

FieldData

spectral_galerkin_heat.io_utils.xdmf_io.write_structured_fields(output_base, fields, x, y, z, time=None, step=None)

Write multiple structured fields to HDF5 + XDMF.

Parameters:

output_base (Path) – Base path for output files (without extension)
fields (Dict[str, np.ndarray]) – Mapping of field names to 3D arrays of shape (nz, ny, nx)
x (np.ndarray) – 1D coordinate arrays
y (np.ndarray) – 1D coordinate arrays
z (np.ndarray) – 1D coordinate arrays
time (float, optional) – Time value
step (int, optional) – Step number

Return type:

None

spectral_galerkin_heat.io_utils.xdmf_io.write_unstructured_fields(output_base, fields, xyz, connectivity, time=None)

Write multiple fields on an unstructured (tetrahedral) mesh to HDF5 + XDMF.

Parameters:

output_base (Path) – Base path for output files (without extension)
fields (Dict[str, np.ndarray]) – Mapping of field names to 1D arrays of shape (n_vertices,)
xyz (np.ndarray) – Vertex coordinates of shape (n_vertices, 3)
connectivity (np.ndarray) – Element connectivity of shape (n_elements, 4) for tetrahedra
time (float, optional) – Time value

Return type:

None