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import xarray as xr
from xcube.core.verify import assert_cube
[docs]def vars_to_dim(cube: xr.Dataset,
dim_name: str = 'var',
var_name='data',
cube_asserted: bool = False):
"""
Convert data variables into a dimension.
:param cube: The xcube dataset.
:param dim_name: The name of the new dimension and coordinate variable. Defaults to 'var'.
:param var_name: The name of the new, single data variable. Defaults to 'data'.
:param cube_asserted: If False, *cube* will be verified, otherwise it is expected to be a valid cube.
:return: A new xcube dataset with data variables turned into a new dimension.
"""
if not cube_asserted:
assert_cube(cube)
if var_name == dim_name:
raise ValueError("var_name must be different from dim_name")
data_var_names = [data_var_name for data_var_name in cube.data_vars]
if not data_var_names:
raise ValueError("cube must not be empty")
da = xr.concat([cube[data_var_name] for data_var_name in data_var_names], dim_name)
new_coord_var = xr.DataArray(data_var_names, dims=[dim_name])
da = da.assign_coords(**{dim_name: new_coord_var})
return xr.Dataset(dict(**{var_name: da}))