'return an instance of CompareMeans with self and other
Parameters
other : array_like or instance of DescrStatsW
If array_like then this creates an instance of DescrStatsW with
the given weights.
weights : None or array
weights are only used if other is not an instance of DescrStatsW
Returns
cm : instance of CompareMeans
the instance has self attached as d1 and other as d2.
See Also
CompareMeans'

def get_compare(self, other, weights=None):

    if (not isinstance(other, self.__class__)):
        d2 = DescrStatsW(other, weights)
    else:
        d2 = other
    return CompareMeans(self, d2)
