'Return a copy sorted along the specified axis.
This is similar to :meth:`~numpy.ndarray.sort`, but internally uses
indexing with :func:`~numpy.lexsort` to ensure that the full precision
given by the two doubles ``jd1`` and ``jd2`` is kept, and that
corresponding attributes are properly sorted and copied as well.
Parameters
axis : int or None
Axis to be sorted.  If ``None``, the flattened array is sorted.
By default, sort over the last axis.'

def sort(self, axis=(-1)):

    return self[self._advanced_index(self.argsort(axis), axis, keepdims=True)]
