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thouis / numpy-trac-migration

numpy Trac to github issues migration
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Provide .H for arrays (migrated from Trac #1638) #3189

Closed thouis closed 12 years ago

thouis commented 12 years ago

Original ticket http://projects.scipy.org/numpy/ticket/1638 Reported 2010-10-14 by trac user nicki, assigned to unknown.

Hi,

I noticed that one difference between numpy arrays and matrices is that ".H" (transpose + conjugation) is only implemented for matrices. ".T", however, being structurally completely equivalent, is implemented for both. A use case for ".H" would be mass dot-products for multivectors.

In any case, this is an inconsistency in numpy.

Cheers, Nico

thouis commented 12 years ago

Comment in Trac by atmention:charris, 2010-10-14

This came up on the list a few years ago. IIRC, the reason not to implement it was that .T is a view of the array data, whereas .H needs to produce a new array because of the conjugation. In any case, I think that you need to raise this issue on the list for discussion.

thouis commented 12 years ago

Comment in Trac by atmention:charris, 2010-10-15

I'm going to close this now. A new bit of information that came from the discussion was that the BLAS dot routine had a flag for conjugation.