in reply to Multiplying matrices

Maybe PDL could be useful here. PDL matrix multiplication

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Re^2: Multiplying matrices
by Ea (Chaplain) on Mar 11, 2014 at 10:51 UTC
    For many years, I too have suggested people look at PDL, but it's only now reflecting on zentara's suggestion that I see PDL could really use some example code up on perlmonks. Unfortunately, I'm not a big PDL user, so you might want to jump onto the PDL mailing list or peruse the Quantified Onion for more knowledgeable answers.

    Taking a stab at an example, would the PDL code look something like this?

    use PDL; # amino acids in this order in the reaction rates pdl # A R N D C Q E G H I L K M F P S T W Y V B Z X $rates = pdl [ [ 5, -2, -1 ], [ -2, 7, -1 ], [ -1, -1, 7 ], ]; $multiplied_rates = $rates x $rates; print $multiplied_rates;
    My calculation by hand seems to agree with the first two values. The rest is left as an exercise for the user.

    Looks a lot easier than the OP's code, if you can overcome the fear of the new. And it's kinda cool :)

    Edit:If I'd checked before posting, I would have linked to The Perl Data Language (PDL): A Quick Reference Guide or RFC: Getting Started with PDL (the Perl Data Language) both of which have lots of examples.

    Sometimes I can think of 6 impossible LDAP attributes before breakfast.