[PYTHON MATRIX-SIG] linear algebra

Konrad HINSEN hinsenk@ere.umontreal.ca
Mon, 19 Aug 1996 12:42:04 -0400

> All of the current interface routines (from LinAlg.py) do the following:
> return transpose(lapackfunction(transpose(input_matrix)))
> Should these two transpositions be there?  This is obviously related to
> the different index order between NumPy and FORTRAN.  Still, I've always
> personally considered it a superficial difference that is best ignored.
> If I remember by Linear Algebra correctly
> transpose(inverse(transpose(m))) == inverse(m).

True for inversion, but for little else, except in the special case of
symmetric matrices.

Personally I think it is important to work with the "right" index
order that everyone is used to. Python users should not have to know
anything about implementation details.

Besides, if I understand everything correctly, transposition should
cost almost nothing, right?


Konrad Hinsen                     | E-Mail: hinsenk@ere.umontreal.ca
Departement de chimie             | Tel.: +1-514-343-6111 ext. 3953
Universite de Montreal            | Fax:  +1-514-343-7586
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