# xarray.Dataset.assign_coords

`Dataset.``assign_coords`(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 of `coords` or `coords_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 same `assign_coords` is possible, but you cannot reference other variables created within the same `assign_coords` call.

  See also

  `Dataset.assign()`, `Dataset.swap_dims()`