XDMF Time Series

XDMF is the only format in meshio++ with built-in support for temporal (time series) data. The mesh topology is written once; field data is written per time step.

Requires h5py when using the default data_format="HDF".

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Writing a time series

import meshioplusplus

with meshioplusplus.xdmf.TimeSeriesWriter("simulation.xdmf") as writer:
    writer.write_points_cells(points, cells)
    for t, phi in time_steps:
        writer.write_data(t, point_data={"phi": phi})

TimeSeriesWriter(filename, data_format="HDF")

Parameter	Default	Description
filename	—	Path to the .xdmf file
data_format	"HDF"	"HDF" (companion .h5), "XML" (inline), or "Binary" (separate .bin files)

Must be used as a context manager (with statement). The .xdmf file is written on __exit__.

writer.write_points_cells(points, cells)

Write the shared mesh topology. Must be called before write_data.

writer.write_data(t, point_data=None, cell_data=None)

Write field data for one time step t (a float). Both point_data and cell_data are dicts of str -> numpy array.

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Reading a time series

with meshioplusplus.xdmf.TimeSeriesReader("simulation.xdmf") as reader:
    points, cells = reader.read_points_cells()
    for k in range(reader.num_steps):
        t, point_data, cell_data = reader.read_data(k)

TimeSeriesReader(filename)

Parses the XDMF file on construction. Only XDMF version 3 is supported for time series.

reader.num_steps

Total number of time steps stored in the file.

reader.read_points_cells()

Returns (points, cells) — the shared mesh topology as a numpy array and a list of CellBlock.

reader.read_data(k)

Returns (t, point_data, cell_data) for time step index k.

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Notes

• The mesh topology is stored once in the XDMF file and referenced by each time step using XInclude.
• With data_format="HDF", all numerical data goes into a companion <stem>.h5 file. Both files must be present to read.
• data_format="XML" embeds all data directly into the XML, which avoids external files but produces large .xdmf files.
• data_format="Binary" writes one .bin file per data array; useful when HDF5 is not available.