Yes, I found the thread you are referring to: http://mail.python.org/pipermail/python-dev/2008-July/081554.html
However, since A*B*C exists for matrices and actually computes (A*B)*C, why not do the same with dot? I.e. why not decide that dot(A,B,C) does what would A*B*C do, i.e., dot(dot(A,B),C)? The performance and precision problems are the responsability of the user, just as with the formula A*B*C. == Olivier 2009/6/7 Robert Kern <robert.k...@gmail.com> > On Sun, Jun 7, 2009 at 02:43, Olivier Verdier <zelb...@gmail.com> wrote: > > There would be a much simpler solution than allowing a new operator. Just > > allow the numpy function dot to take more than two arguments. Then A*B*C > in > > matrix notation would simply be: > > dot(A,B,C) > > with arrays. Wouldn't that make everybody happy? Plus it does not break > > backward compatibility. Am I missing something? > > We've discussed it before. Search the archives. Although matrix > multiplication is mathematically associative, there are performance > and precision implications to the order the multiplications happen. No > satisfactory implementation was found. > > -- > Robert Kern > > "I have come to believe that the whole world is an enigma, a harmless > enigma that is made terrible by our own mad attempt to interpret it as > though it had an underlying truth." > -- Umberto Eco > _______________________________________________ > Numpy-discussion mailing list > Numpy-discussion@scipy.org > http://mail.scipy.org/mailman/listinfo/numpy-discussion >
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