in reply to Shuffling CODONS

My favorite shuffle 

#!/usr/bin/perl

# http://perlmonks.org/?node_id=1216102

use strict;
use warnings;

my @trips = 'a' .. 'z';

my @shuftrips = myshuffle( @trips );

print "@shuftrips\n";

sub myshuffle
  {
  map $_->[0],
    sort { $a->[1] <=> $b->[1] }
    map [ $_, rand ], @_;
  }

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Re^2: Shuffling CODONS
by BrowserUk (Patriarch) on Jun 07, 2018 at 14:41 UTC

    Why is that a favorite? I get it'll shuffle anything correctly, but trading O(NlogN) for O(1) is painful:

    <Reveal this spoiler or all in this thread>

    Benchmark:

               Rate   tybalt     buk1     buk2 ListUtil
tybalt    224/s       --     -65%     -70%     -97%
buk1      644/s     187%       --     -14%     -91%
buk2      746/s     233%      16%       --     -90%
ListUtil 7342/s    3176%    1040%     884%       --

C:\test>shufflesBenchmark2018.pl -SIZE=1e3
           Rate   tybalt     buk1     buk2 ListUtil
tybalt    229/s       --     -66%     -70%     -97%
buk1      675/s     195%       --     -13%     -91%
buk2      776/s     238%      15%       --     -89%
ListUtil 7339/s    3102%     987%     846%       --

C:\test>shufflesBenchmark2018.pl -SIZE=1e4
           Rate   tybalt     buk1     buk2 ListUtil
tybalt   17.2/s       --     -75%     -78%     -98%
buk1     67.5/s     292%       --     -13%     -90%
buk2     77.2/s     349%      14%       --     -89%
ListUtil  704/s    3992%     944%     812%       --

C:\test>shufflesBenchmark2018.pl -SIZE=1e5
            (warning: too few iterations for a reliable count)

           Rate   tybalt     buk1     buk2 ListUtil
tybalt   1.21/s       --     -81%     -84%     -98%
buk1     6.40/s     430%       --     -15%     -89%
buk2     7.53/s     523%      18%       --     -87%
ListUtil 56.4/s    4566%     781%     649%       --

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    Examine what is said, not who speaks -- Silence betokens consent -- Love the truth but pardon error.
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Re^2: Shuffling CODONS
by WouterVG (Novice) on Jun 07, 2018 at 14:02 UTC

    Thanks for your reply! If I implement it like below. It doesn't change the order of codons. 

     print "enter sequence and signal end with enter followed by ctrl d\n"
+;
$sequence = <STDIN>;
chomp $sequence;
print "sequence inserted : $sequence\n";
@trips = unpack("a3" x (length($sequence)-2), $sequence);
@trips = join(" ", @trips);

my @shuftrips = &myshuffle( @trips );

print "@shuftrips\n";

sub myshuffle
  {
  map $_->[0],
    sort { $a->[1] <=> $b->[1] }
    map [ $_, rand ], @_;
  }

    [download]
[reply]
[d/l]

      Because @trips = join(" ", @trips); joins all codons into ONE string!

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[d/l]

        ^^^ THIS

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