Estimate the covariance matrix.
Except for the handling of missing data this function does the same as numpy.cov. For more details and examples, see numpy.cov.
By default, masked values are recognized as such. If x and y have the same shape, a common mask is allocated: if x[i,j] is masked, then y[i,j] will also be masked. Setting allow_masked to False will raise an exception if values are missing in either of the input arrays.
Parameters :  x : array_like
y : array_like, optional
rowvar : bool, optional
bias : bool, optional
allow_masked : bool, optional
ddof : {None, int}, optional


Raises :  ValueError: :

See also