Cylindrical EPOCH support

[JoelLucaAdams]

Currently we don't support cylindrical EPOCH (CE). Upon running a preliminary test using the example deck gaussian_pulse.deck it falls over when attempting to acquire the grid for a given variable.

>>> ds = sdfxr.open_dataset("/Users/joel/Source/cylindrical_epoch/epoch_axial/test/0001.sdf")

File ~/Source/sdf-xarray/src/sdf_xarray/__init__.py:855, in SDFDataStore.load(self)
    852 dim_size_lookup = defaultdict(dict)
--> 853 grid = self.ds.grids[value.grid]
    856 grid_base_name = _process_grid_name(grid.name, _norm_grid_name)
    857 for dim_size, dim_name in zip(grid.shape, grid.labels):

KeyError: 'mode_grid'

This is due to the mode_grid not existing in the list of grids

>>> sdfxr.SDFFile("/Users/joel/Source/cylindrical_epoch/epoch_axial/test/0000.sdf").grids

{'grid': Mesh(_id='grid', name='Grid/Grid', dtype=dtype('float64'), shape=(501, 101), is_point_data=False, sdffile=<sdf_xarray.sdf_interface.SDFFile object at 0x11d076680>, units=('m', 'm'), labels=('X', 'Y'), mults=(1.0, 1.0), parent=None),
 'grid_mid': Mesh(_id='grid', name='Grid/Grid_mid', dtype=dtype('float64'), shape=(500, 100), is_point_data=False, sdffile=<sdf_xarray.sdf_interface.SDFFile object at 0x11d076680>, units=('m', 'm'), labels=('X', 'Y'), mults=(1.0, 1.0), parent=Mesh(_id='grid', name='Grid/Grid', dtype=dtype('float64'), shape=(501, 101), is_point_data=False, sdffile=<sdf_xarray.sdf_interface.SDFFile object at 0x11d076680>, units=('m', 'm'), labels=('X', 'Y'), mults=(1.0, 1.0), parent=None)),
 'grid_cpu_rank': Mesh(_id='grid_cpu_rank', name='Grid/CPUs/Original rank', dtype=dtype('float64'), shape=(3, 5), is_point_data=False, sdffile=<sdf_xarray.sdf_interface.SDFFile object at 0x11d076680>, units=('m', 'm'), labels=('X', 'Y'), mults=None, parent=None),
 'grid_cpu_rank_mid': Mesh(_id='grid_cpu_rank', name='Grid/CPUs/Original rank_mid', dtype=dtype('float64'), shape=(2, 4), is_point_data=False, sdffile=<sdf_xarray.sdf_interface.SDFFile object at 0x11d076680>, units=('m', 'm'), labels=('X', 'Y'), mults=None, parent=Mesh(_id='grid_cpu_rank', name='Grid/CPUs/Original rank', dtype=dtype('float64'), shape=(3, 5), is_point_data=False, sdffile=<sdf_xarray.sdf_interface.SDFFile object at 0x11d076680>, units=('m', 'm'), labels=('X', 'Y'), mults=None, parent=None)),
 'grid_cpus_current': Mesh(_id='grid_cpus_current', name='Grid/CPUs/Current rank', dtype=None, shape=(2, 2), is_point_data=False, sdffile=<sdf_xarray.sdf_interface.SDFFile object at 0x11d076680>, units=('m', 'm'), labels=('X', 'Y'), mults=None, parent=None),
 'grid_cpus_current_mid': Mesh(_id='grid_cpus_current', name='Grid/CPUs/Current rank_mid', dtype=None, shape=(1, 1), is_point_data=False, sdffile=<sdf_xarray.sdf_interface.SDFFile object at 0x11d076680>, units=('m', 'm'), labels=('X', 'Y'), mults=None, parent=Mesh(_id='grid_cpus_current', name='Grid/CPUs/Current rank', dtype=None, shape=(2, 2), is_point_data=False, sdffile=<sdf_xarray.sdf_interface.SDFFile object at 0x11d076680>, units=('m', 'm'), labels=('X', 'Y'), mults=None, parent=None))}

However all the variables in the file are using it

>>> sdfxr.SDFFile("/Users/joel/Source/cylindrical_epoch/epoch_axial/test/0000.sdf").variables

{'Wall-time': Constant(_id='elapsed_time', name='Wall-time', data=0.002371000000000012, units=None),
 'Electric Field Modes/Exm/real': Variable(_id='exm_real', name='Electric Field Modes/Exm/real', dtype=dtype('float64'), shape=(500, 100, 2), is_point_data=False, sdffile=<sdf_xarray.sdf_interface.SDFFile object at 0x11d15da80>, units='V/m', mult=1.0, grid='mode_grid', grid_mid='mode_grid_mid'),
 'Electric Field Modes/Erm/real': Variable(_id='erm_real', name='Electric Field Modes/Erm/real', dtype=dtype('float64'), shape=(500, 100, 2), is_point_data=False, sdffile=<sdf_xarray.sdf_interface.SDFFile object at 0x11d15da80>, units='V/m', mult=1.0, grid='mode_grid', grid_mid='mode_grid_mid'),
 'Electric Field Modes/Etm/real': Variable(_id='etm_real', name='Electric Field Modes/Etm/real', dtype=dtype('float64'), shape=(500, 100, 2), is_point_data=False, sdffile=<sdf_xarray.sdf_interface.SDFFile object at 0x11d15da80>, units='V/m', mult=1.0, grid='mode_grid', grid_mid='mode_grid_mid'),
 'Electric Field Modes/Exm/imag': Variable(_id='exm_imag', name='Electric Field Modes/Exm/imag', dtype=dtype('float64'), shape=(500, 100, 2), is_point_data=False, sdffile=<sdf_xarray.sdf_interface.SDFFile object at 0x11d15da80>, units='V/m', mult=1.0, grid='mode_grid', grid_mid='mode_grid_mid'),
 'Electric Field Modes/Erm/imag': Variable(_id='erm_imag', name='Electric Field Modes/Erm/imag', dtype=dtype('float64'), shape=(500, 100, 2), is_point_data=False, sdffile=<sdf_xarray.sdf_interface.SDFFile object at 0x11d15da80>, units='V/m', mult=1.0, grid='mode_grid', grid_mid='mode_grid_mid'),
 'Electric Field Modes/Etm/imag': Variable(_id='etm_imag', name='Electric Field Modes/Etm/imag', dtype=dtype('float64'), shape=(500, 100, 2), is_point_data=False, sdffile=<sdf_xarray.sdf_interface.SDFFile object at 0x11d15da80>, units='V/m', mult=1.0, grid='mode_grid', grid_mid='mode_grid_mid'),
 'Magnetic Field Modes/Bxm/real': Variable(_id='bxm_real', name='Magnetic Field Modes/Bxm/real', dtype=dtype('float64'), shape=(500, 100, 2), is_point_data=False, sdffile=<sdf_xarray.sdf_interface.SDFFile object at 0x11d15da80>, units='T', mult=1.0, grid='mode_grid', grid_mid='mode_grid_mid'),
 'Magnetic Field Modes/Brm/real': Variable(_id='brm_real', name='Magnetic Field Modes/Brm/real', dtype=dtype('float64'), shape=(500, 100, 2), is_point_data=False, sdffile=<sdf_xarray.sdf_interface.SDFFile object at 0x11d15da80>, units='T', mult=1.0, grid='mode_grid', grid_mid='mode_grid_mid'),
 'Magnetic Field Modes/Btm/real': Variable(_id='btm_real', name='Magnetic Field Modes/Btm/real', dtype=dtype('float64'), shape=(500, 100, 2), is_point_data=False, sdffile=<sdf_xarray.sdf_interface.SDFFile object at 0x11d15da80>, units='T', mult=1.0, grid='mode_grid', grid_mid='mode_grid_mid'),
 'Magnetic Field Modes/Bxm/imag': Variable(_id='bxm_imag', name='Magnetic Field Modes/Bxm/imag', dtype=dtype('float64'), shape=(500, 100, 2), is_point_data=False, sdffile=<sdf_xarray.sdf_interface.SDFFile object at 0x11d15da80>, units='T', mult=1.0, grid='mode_grid', grid_mid='mode_grid_mid'),
 'Magnetic Field Modes/Brm/imag': Variable(_id='brm_imag', name='Magnetic Field Modes/Brm/imag', dtype=dtype('float64'), shape=(500, 100, 2), is_point_data=False, sdffile=<sdf_xarray.sdf_interface.SDFFile object at 0x11d15da80>, units='T', mult=1.0, grid='mode_grid', grid_mid='mode_grid_mid'),
 'Magnetic Field Modes/Btm/imag': Variable(_id='btm_imag', name='Magnetic Field Modes/Btm/imag', dtype=dtype('float64'), shape=(500, 100, 2), is_point_data=False, sdffile=<sdf_xarray.sdf_interface.SDFFile object at 0x11d15da80>, units='T', mult=1.0, grid='mode_grid', grid_mid='mode_grid_mid'),
 'CPUs/Original rank': Variable(_id='cpu_rank', name='CPUs/Original rank', dtype=dtype('int32'), shape=(2, 4), is_point_data=False, sdffile=<sdf_xarray.sdf_interface.SDFFile object at 0x11d15da80>, units='CPU', mult=None, grid='grid_cpu_rank', grid_mid='grid_cpu_rank_mid'),
 'CPUs/Current rank': Variable(_id='cpus_current', name='CPUs/Current rank', dtype=dtype('int32'), shape=(0, 0), is_point_data=False, sdffile=<sdf_xarray.sdf_interface.SDFFile object at 0x11d15da80>, units='CPU', mult=None, grid='grid_cpus_current', grid_mid='grid_cpus_current_mid')}

This leads to quite a difficult issue to deal with that is unique to CE's implementation. One of the flags I was considering using to check if the code being run is cylindrical was the code_name from the attributes but unfortunately this is set to "Epoch2d" so no different to the original EPOCH code when running in 2D....