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.kern@gmail.com>
On Sun, Jun 7, 2009 at 02:43, Olivier Verdier <zelbier@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
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