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Re: how to get average of matrices' elements?

by choroba (Cardinal)
on Nov 30, 2016 at 23:35 UTC ( [id://1177000]=note: print w/replies, xml ) Need Help??


in reply to how to get average of matrices' elements?

To work with matrices, use PDL.

Update

I've got it! It's super easy. Just pile the matrices one on another, and then project the 3D matrix by average in the z dimension:

#!/usr/bin/perl use warnings; use strict; use PDL; sub load { my ($filename) = @_; open my $FH, '<', $filename or die $!; return pdl(map [split], <$FH>) } my $matrix = cat(map load($_), @ARGV); print average($matrix->reorder(2,0,1));

Old contents

I'm not yet familiar with it, so I had to compute the average myself by adding the matrices and dividing the result by their number, but maybe there already is a function to compute the average per element, or at least to apply a function per element.

#!/usr/bin/perl use warnings; use strict; use feature qw{ say }; use PDL; sub load { my ($filename) = @_; open my $FH, '<', $filename or die $!; return pdl(join "\n", map { chomp; "[$_]" } <$FH>) } my @matrices = map load($_), @ARGV; my $result = $matrices[0]; $result += $_ for @matrices[ 1 .. $#matrices ]; $result /= @ARGV; say $result;
($q=q:Sq=~/;[c](.)(.)/;chr(-||-|5+lengthSq)`"S|oS2"`map{chr |+ord }map{substrSq`S_+|`|}3E|-|`7**2-3:)=~y+S|`+$1,++print+eval$q,q,a,

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Re^2: how to get average of matrices' elements?
by etj (Deacon) on May 19, 2022 at 16:07 UTC
    Tiny note: an easier way to get the dimension you want to average over to the 0 position than reorder is mv. That also can take negative numbers which count backwards from end, leading to this very common idiom:
    print $matrix->mv(-1,0)->avgover;

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