def lonlat_to_xy(longitude: xr.DataArray,
latitude: xr.DataArray,
epsg: int = 3031) -> (xr.DataArray, xr.DataArray):
"""
Reprojects longitude/latitude EPSG:4326 coordinates to x/y coordinates.
Default conversion is to Antarctic Stereographic Projection EPSG:3031.
"""
if hasattr(longitude, "__array__") and callable(longitude.__array__):
# TODO upgrade to PyProj 3.0 to remove this workaround for passing in
# dask.dataframe.core.Series or xarray.DataArray objects
# Based on https://github.com/pyproj4/pyproj/pull/625
_longitude = longitude.__array__()
_latitude = latitude.__array__()
x, y = pyproj.Proj(projparams=epsg)(_longitude, _latitude)
if hasattr(longitude, "coords"):
return (
xr.DataArray(data=x, coords=longitude.coords),
xr.DataArray(data=y, coords=latitude.coords),
)
else:
return x, y
