xarray.DataArray.reindex#

DataArray.reindex(indexers=None, *, method=None, tolerance=None, copy=True, fill_value=<NA>, **indexers_kwargs)[source]#

Conform this object onto the indexes of another object, filling in missing values with fill_value. The default fill value is NaN.

Parameters:

indexers (dict, optional) – Dictionary with keys given by dimension names and values given by arrays of coordinates tick labels. Any mismatched coordinate values will be filled in with NaN, and any mismatched dimension names will simply be ignored. One of indexers or indexers_kwargs must be provided.
copy (bool, optional) – If copy=True, data in the return value is always copied. If copy=False and reindexing is unnecessary, or can be performed with only slice operations, then the output may share memory with the input. In either case, a new xarray object is always returned.
method ({None, 'nearest', 'pad'/'ffill', 'backfill'/'bfill'}, optional) – Method to use for filling index values in indexers not found on this data array:
- None (default): don’t fill gaps
- pad / ffill: propagate last valid index value forward
- backfill / bfill: propagate next valid index value backward
- nearest: use nearest valid index value
tolerance (float | Iterable[float] | str | None, default: None) – Maximum distance between original and new labels for inexact matches. The values of the index at the matching locations must satisfy the equation abs(index[indexer] - target) <= tolerance. Tolerance may be a scalar value, which applies the same tolerance to all values, or list-like, which applies variable tolerance per element. List-like must be the same size as the index and its dtype must exactly match the index’s type.
fill_value (scalar or dict-like, optional) – Value to use for newly missing values. If a dict-like, maps variable names (including coordinates) to fill values. Use this data array’s name to refer to the data array’s values.
**indexers_kwargs ({dim: indexer, ...}, optional) – The keyword arguments form of indexers. One of indexers or indexers_kwargs must be provided.

Returns:

reindexed (DataArray) – Another dataset array, with this array’s data but replaced coordinates.

Examples

Reverse latitude:

>>> da = xr.DataArray(
...     np.arange(4),
...     coords=[np.array([90, 89, 88, 87])],
...     dims="lat",
... )
>>> da
<xarray.DataArray (lat: 4)> Size: 32B
array([0, 1, 2, 3])
Coordinates:
  * lat      (lat) int64 32B 90 89 88 87
>>> da.reindex(lat=da.lat[::-1])
<xarray.DataArray (lat: 4)> Size: 32B
array([3, 2, 1, 0])
Coordinates:
  * lat      (lat) int64 32B 87 88 89 90