http://qs321.pair.com?node_id=1062161


in reply to Sort over remaining part of array

I would like to sort it on the 1st column ($a are numerical, $b and $c are strings), take it line by line - if $b was seen before, resample $a and $b, then sort the remaining rows in array (including the current one) and analyze as before - until all $b's are unique.

Can you translate that into simple english please? And maybe post real sample data instead of "$a0"...?

Thanks

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Re^2: Sort over remaining part of array
by Anonymous Monk on Nov 12, 2013 at 10:39 UTC

    I'd sort first, then remove duplicates

    I've still no idea what resample means 

    #!/usr/bin/perl --
use strict; use warnings; use Data::Dump qw/ dd pp /;
my @AoA = (
           [ 0.5, "b1", "c0" ],
           [ 0.4, "b1", "c1" ],
           [ 0.7, "b2", "c2" ],
           [ 0.3, "b3", "c3" ],
           [ 0.6, "b3", "c4" ],
);

dd\@AoA;
@AoA = sort { $$b[0] <=> $$a[0] } @AoA;
dd\@AoA;
{ my %seen;
  @AoA = grep{!$seen{$$_[1]}++}@AoA;
}
dd\@AoA;
__END__
[
  [0.5, "b1", "c0"],
  [0.4, "b1", "c1"],
  [0.7, "b2", "c2"],
  [0.3, "b3", "c3"],
  [0.6, "b3", "c4"],
]
[
  [0.7, "b2", "c2"],
  [0.6, "b3", "c4"],
  [0.5, "b1", "c0"],
  [0.4, "b1", "c1"],
  [0.3, "b3", "c3"],
]
[[0.7, "b2", "c2"], [0.6, "b3", "c4"], [0.5, "b1", "c0"]]

    [download]

    Also worth considering are Sort::Key - the fastest way to sort anything in Perl

    and Sort::Key::External allows to sort huge lists that do not fit in the available memory.

[reply]
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