[Numpy-discussion] numarray cov function

[Travis Oliphant]

John Hunter wrote:
> I was surprised to see that numarray.mlab.cov is returning a rank-0
> complex number when given two 1D arrays as inputs rather than the
> standard 2x2 covariance array I am used to seeing.  Is this a feature
> or a bug?  
>
>
> In [2]: import numarray.mlab as nam
>
> In [3]: x = nam.rand(10)
>
> In [4]: y = nam.rand(10)  
>
> In [5]: nam.cov(x, y)
> Out[5]: array((0.014697855954587828+0j))
>
> In [6]: import numpy.oldnumeric.mlab as npm
>
> In [7]: x = npm.rand(10)
>
> In [8]: y = npm.rand(10)
>
> In [9]: npm.cov(x, y)
> Out[9]: 
> array([[ 0.13243082,  0.0520454 ],
>        [ 0.0520454 ,  0.07435816]])
>
> In [10]: import numarray
>
> In [11]: numarray.__version__
> Out[11]: '1.3.3'
>
> In [12]: import numpy
>
> In [13]: numpy.__version__
> Out[13]: '1.0b2.dev2999'
>
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