matrices

[Jeff Abrahamson <jeff@purple.com>]

I've been looking at matrix packages. Looks like Math::Matrix is the
one to use, but it's not very mature. Worse, performance is
aweful.

I tried the following comparison with newmat (a C++ library) compiled
without optimization. I loaded a 500 x 500 matrix with random values
and then computed the first eleven powers (a^2, a^3, ..., a^11). The
profile of the two is

    C++:  0 seconds to load, 15 seconds to multiply
    perl: 1 second to load, ---

(600 seconds later, the perl version still hadn't finished, so I tried
just a single multiplication: 161 seconds)


Has anyone here tried doing anything with matrix multiplication in
perl? Based on the above, it doesn't seem like a reasonable thing to
do. I was ready for a factor of two speed hit, but not two orders of
magnitude.

-- 
 Jeff

 Jeff Abrahamson  <http://www.purple.com/jeff/>
 GPG fingerprint: 1A1A BA95 D082 A558 A276  63C6 16BF 8C4C 0D1D AE4B

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