Develop vtk-xarray interface

[johnkit]

Develop an Xarray acessor for importing numpy data from Xarray arrays and converting to the applicable vtkDataSet type. Use https://github.com/pyvista/pyvista-xarray as an exemplar.

Xarray accessor documentation at https://docs.xarray.dev/en/stable/internals/extending-xarray.html

First step probably an explicit function to return vtkDataSet from input numpy arrays for coordinates & values.

• optional args to specify x, y, [z], [time]
• also let's copy Bane's heuristic for assigning coords
• future add conduit/blueprint and/or Fides option to specify grid type, coordinate arrays, & data arrays

To start, let's support "current" examples (rectilinear, structured, image)

[johnkit]

See the example at https://github.com/pyvista/pyvista-xarray:

Previous (pyvista-xarray module)

import pvxarray
import xarray as xr

ds = xr.tutorial.load_dataset("air_temperature")
da = ds.air[dict(time=0)]  # Select DataArray for a timestep

# Plot in 3D
da.pyvista.plot(x="lon", y="lat", show_edges=True, cpos='xy')

# Or grab the mesh object for use with PyVista
mesh = da.pyvista.mesh(x="lon", y="lat")

Todo (vtk-xarray module)

import vtk_xarray    # <== new module
import xarray as xr

ds = xr.tutorial.load_dataset("air_temperature")
da = ds.air[dict(time=0)]  # Select DataArray for a timestep

# Get/create corresponding mesh object
mesh = da.vtk.mesh(x="lon", y="lat")    # <== da.vtk property replaces da.pyvista

# Plot in 3D
# ...

[johnkit]

Superseded by #106