in reply to Comparing two arrays
My end result is not to know, for each (x,y) array how many 1's they share just to know what are the top 10 y arrays that share the most 1' with each x array.
Convert your arrays of 0s 1s to bit-strings, then use bitwise-& and unpack '%32b*' to count the equivalences and you can do this 300+ times faster than comparing the arrays:
#! perl -slw use strict; use Benchmark qw[ cmpthese ]; use Data::Dump qw[ pp ]; $Data::Dump::WIDTH = 500; our $I //= -1; our $N //= 1000; our @xArrays = map[ map int( rand 2 ), 1 .. 15_000 ], 1 .. $N; our @yArrays = map[ map int( rand 2 ), 1 .. 15_000 ], 1 .. $N; our @xStrings = map{ join '', @$_ } @xArrays; our @yStrings = map{ join '', @$_ } @yArrays; our @xBits = map{ pack 'b*', $_ } @xStrings; our @yBits = map{ pack 'b*', $_ } @yStrings; cmpthese $I, { array => q[ my %top10s; for my $x ( 0 .. $#xArrays ) { for my $y ( 0 .. $#yArrays ) { my $count = 0; $xArrays[$x][$_] == 1 && $yArrays[$y][$_] == 1 and ++$ +count for 0 .. $#{ $xArrays[ 0 ] }; $top10s{"$x:$y"} = $count; my $discard = ( sort{ $top10s{$a} <=> $top10s{$b} } ke +ys %top10s )[ 0 ]; keys( %top10s ) > 10 and delete $top10s{$discard}; } } $I == 1 and pp ' arrays: ', %top10s; ], strings => q[ my %top10s; for my $x ( 0 .. $#xStrings ) { for my $y ( 0 .. $#yStrings ) { my $count = ( $xStrings[$x] & $yStrings[$y] ) =~ tr[1] +[]; $top10s{"$x:$y"} = $count; my $discard = ( sort{ $top10s{$a} <=> $top10s{$b} } ke +ys %top10s )[ 0 ]; keys( %top10s ) > 10 and delete $top10s{$discard}; } } $I == 1 and pp 'strings: ', %top10s; ], bits => q[ my %top10s; for my $x ( 0 .. $#xBits ) { for my $y ( 0 .. $#yBits ) { my $count = unpack '%32b*', ( $xBits[$x] & $yBits[$y] +); $top10s{"$x:$y"} = $count; my $discard = ( sort{ $top10s{$a} <=> $top10s{$b} } ke +ys %top10s )[ 0 ]; keys( %top10s ) > 10 and delete $top10s{$discard}; } } $I == 1 and pp ' bits: ', %top10s; ], }; __END__ C:\test>1067218 -N=100 Rate array strings bits array 1.95e-002/s -- -98% -100% strings 1.08/s 5417% -- -82% bits 5.97/s 30510% 455% --
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Re^2: Comparing two arrays
by baxy77bax (Deacon) on Dec 15, 2013 at 12:58 UTC | |
by BrowserUk (Patriarch) on Dec 15, 2013 at 13:47 UTC | |
by hdb (Monsignor) on Dec 15, 2013 at 14:03 UTC | |
by BrowserUk (Patriarch) on Dec 30, 2013 at 22:29 UTC |
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