xarray.align(*objects, join='inner', copy=True, indexes=None, exclude=frozenset({}), fill_value=<NA>)

Given any number of Dataset and/or DataArray objects, returns new objects with aligned indexes and dimension sizes.

Array from the aligned objects are suitable as input to mathematical operators, because along each dimension they have the same index and size.

Missing values (if join != 'inner') are filled with fill_value. The default fill value is NaN.

*objectsDataset or DataArray

Objects to align.

join{‘outer’, ‘inner’, ‘left’, ‘right’, ‘exact’}, optional

Method for joining the indexes of the passed objects along each dimension:

  • ‘outer’: use the union of object indexes

  • ‘inner’: use the intersection of object indexes

  • ‘left’: use indexes from the first object with each dimension

  • ‘right’: use indexes from the last object with each dimension

  • ‘exact’: instead of aligning, raise ValueError when indexes to be aligned are not equal

copybool, optional

If copy=True, data in the return values 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, new xarray objects are always returned.

indexesdict-like, optional

Any indexes explicitly provided with the indexes argument should be used in preference to the aligned indexes.

excludesequence of str, optional

Dimensions that must be excluded from alignment

fill_valuescalar, optional

Value to use for newly missing values

alignedsame as *objects

Tuple of objects with aligned coordinates.


If any dimensions without labels on the arguments have different sizes, or a different size than the size of the aligned dimension labels.