xarray.DataArray.assign_coords¶
-
DataArray.
assign_coords
(self, coords=None, **coords_kwargs)¶ Assign new coordinates to this object.
Returns a new object with all the original data in addition to the new coordinates.
- Parameters
coords (dict, optional) – A dict with keys which are variables names. If the values are callable, they are computed on this object and assigned to new coordinate variables. If the values are not callable, (e.g. a
DataArray
, scalar, or array), they are simply assigned.**coords_kwargs (keyword, value pairs, optional) – The keyword arguments form of
coords
. One ofcoords
orcoords_kwargs
must be provided.
- Returns
assigned – A new object with the new coordinates in addition to the existing data.
- Return type
same type as caller
Examples
Convert longitude coordinates from 0-359 to -180-179:
>>> da = xr.DataArray(np.random.rand(4), ... coords=[np.array([358, 359, 0, 1])], ... dims='lon') >>> da <xarray.DataArray (lon: 4)> array([0.28298 , 0.667347, 0.657938, 0.177683]) Coordinates: * lon (lon) int64 358 359 0 1 >>> da.assign_coords(lon=(((da.lon + 180) % 360) - 180)) <xarray.DataArray (lon: 4)> array([0.28298 , 0.667347, 0.657938, 0.177683]) Coordinates: * lon (lon) int64 -2 -1 0 1
The function also accepts dictionary arguments:
>>> da.assign_coords({'lon': (((da.lon + 180) % 360) - 180)}) <xarray.DataArray (lon: 4)> array([0.28298 , 0.667347, 0.657938, 0.177683]) Coordinates: * lon (lon) int64 -2 -1 0 1
Notes
Since
coords_kwargs
is a dictionary, the order of your arguments may not be preserved, and so the order of the new variables is not well defined. Assigning multiple variables within the sameassign_coords
is possible, but you cannot reference other variables created within the sameassign_coords
call.See also