'construct a CompareMeans object from data
Parameters
data1, data2 : array-like, 1-D or 2-D
compared datasets
weights1, weights2 : None or 1-D ndarray
weights for each observation of data1 and data2 respectively,
with same length as zero axis of corresponding dataset.
ddof1, ddof2 : int
default ddof1=0, ddof2=0, degrees of freedom for data1,
data2 respectively.
Returns
A CompareMeans instance.'

@classmethod
def from_data(cls, data1, data2, weights1=None, weights2=None, ddof1=0, ddof2=0):

    return cls(DescrStatsW(data1, weights=weights1, ddof=ddof1), DescrStatsW(data2, weights=weights2, ddof=ddof2))
