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How do I do filtering in Perl (keep sort order and sort again by another means)?

Ok, I have a list of items and associated values that were pre-sorted according to value. Some values are the same so I want to sort those by name as well. Here's what I mean:

Desired Output:

Code:

pink|3.3

salmon|3.3

brown|3.0

orange|3.0

peach|3.0

red|3.0

tan|3.0

mustard|2.5

yellow|2.2

gold|1.8

green|1.8

hunter|1.8

lime|1.8

aqua|1.5

blue|1.5

cornflower|1.5

cyan|1.5

indigo|1.5

ivory|1.5

lavender|1.5

magenta|1.5

periwinkle|1.5

purple|1.5

sky|1.5

teal|1.5

violet|1.5

white|1.5

ecru|1.3

charcoal|1.1

eggshell|1.1

gray|1.1

black|1.0

Note that values that are the same are also sorted alphabetically. Now, here's my code, and the actual output:

Code:



#!/usr/bin/perl

use strict;

use Data::Dumper;



my @arr_data = (

                                "pink|3.3",

                                "salmon|3.3",

                                "red|3.0",

                                "orange|3.0",

                                "peach|3.0",

                                "tan|3.0",

                                "brown|3.0",

                                "mustard|2.5",

                                "yellow|2.2",

                                "gold|1.8",

                                "lime|1.8",

                                "green|1.8",

                                "hunter|1.8",

                                "blue|1.5",

                                "sky|1.5",

                                "periwinkle|1.5",

                                "aqua|1.5",

                                "cyan|1.5",

                                "teal|1.5",

                                "indigo|1.5",

                                "violet|1.5",

                                "lavender|1.5",

                                "purple|1.5",

                                "magenta|1.5",

                                "cornflower|1.5",

                                "white|1.5",

                                "ivory|1.5",

                                "ecru|1.3",

                                "eggshell|1.1",

                                "gray|1.1",

                                "charcoal|1.1",

                                "black|1.0"

                                );



my (@temp, @index, @sorter, @sorted);

my ($item, $i);

foreach $item (@arr_data) {

        @temp = split("[\|]", $item);



        # Find index of others with same value

        @index = grep { $arr_data[$_] =~ /$temp[1]/ } 0..$#arr_data;



        # get the data

        undef @sorter;

        foreach $i (@index) {



                # add to sorter array

                $sorter[$#sorter + 1] = $arr_data[$i];



                # remove from old array

                splice @arr_data, $i, 1; 



        }



        # sort alphabetically

        @sorter = sort(@sorter);



        # add to new array

        @sorted = (@sorted, @sorter); 

}



# *** DEBUG ***

print Dumper(@sorted);

# *** END DEBUG ***

Output:

Code:

$VAR1 = 'pink|3.3';

$VAR2 = 'red|3.0';

$VAR3 = 'gold|1.8';

$VAR4 = 'mustard|2.5';

$VAR5 = 'orange|3.0';

$VAR6 = 'tan|3.0';

$VAR7 = 'peach|3.0';

$VAR8 = 'yellow|2.2';

$VAR9 = 'hunter|1.8';

$VAR10 = 'lime|1.8';

$VAR11 = 'sky|1.5';

$VAR12 = undef;

$VAR13 = undef;

$VAR14 = undef;

$VAR15 = undef;

$VAR16 = 'aqua|1.5';

$VAR17 = 'blue|1.5';

$VAR18 = 'charcoal|1.1';

$VAR19 = 'cornflower|1.5';

$VAR20 = 'eggshell|1.1';

$VAR21 = 'ivory|1.5';

$VAR22 = 'purple|1.5';

$VAR23 = 'teal|1.5';

$VAR24 = 'violet|1.5';

$VAR25 = undef;

$VAR26 = 'black|1.0';

$VAR27 = 'ecru|1.3';

$VAR28 = 'indigo|1.5';

$VAR29 = 'magenta|1.5';

$VAR30 = 'periwinkle|1.5';

$VAR31 = 'gray|1.1';

I'm just not sure how to approach this. Any help would be appreciated. Thanks!

can you not use sort?
it would much easier.
i.e. not perl.

You can do this type of thing by writing a custom sort subroutine. Here is a quick stab. It works, but there are probably more efficient ways to do it:

Code:

#!/usr/bin/perl

use warnings;

use strict;



my @arr_data = (

        "pink|3.3",

        "salmon|3.3",

        "red|3.0",

        "orange|3.0",

        "peach|3.0",

        "tan|3.0",

        "brown|3.0",

        "mustard|2.5",

        "yellow|2.2",

        "gold|1.8",

        "lime|1.8",

        "green|1.8",

        "hunter|1.8",

        "blue|1.5",

        "sky|1.5",

        "periwinkle|1.5",

        "aqua|1.5",

        "cyan|1.5",

        "teal|1.5",

        "indigo|1.5",

        "violet|1.5",

        "lavender|1.5",

        "purple|1.5",

        "magenta|1.5",

        "cornflower|1.5",

        "white|1.5",

        "ivory|1.5",

        "ecru|1.3",

        "eggshell|1.1",

        "gray|1.1",

        "charcoal|1.1",

        "black|1.0"

);



my @sorted = sort my_way @arr_data;



sub my_way {

  my($name_a, $value_a) = split /\|/, $a;

  my($name_b, $value_b) = split /\|/, $b;



  $value_b <=> $value_a or $name_a cmp $name_b;

}



foreach my $line (@sorted) {

  print "\t$line\n";

}

The output is what you want. I'll leave printing it out for folks to do on their own (rather than take up space here).

Edit: If you want the original array itself sorted just do

Code:

@arry_data = sort my_way @arr_data;

A second way which is a lot more complicated to look at, but perhaps more efficient:

Code:

#!/usr/bin/perl

use warnings;

use strict;



my @arr_data = (

        "pink|3.3",

        "salmon|3.3",

        "red|3.0",

        "orange|3.0",

        "peach|3.0",

        "tan|3.0",

        "brown|3.0",

        "mustard|2.5",

        "yellow|2.2",

        "gold|1.8",

        "lime|1.8",

        "green|1.8",

        "hunter|1.8",

        "blue|1.5",

        "sky|1.5",

        "periwinkle|1.5",

        "aqua|1.5",

        "cyan|1.5",

        "teal|1.5",

        "indigo|1.5",

        "violet|1.5",

        "lavender|1.5",

        "purple|1.5",

        "magenta|1.5",

        "cornflower|1.5",

        "white|1.5",

        "ivory|1.5",

        "ecru|1.3",

        "eggshell|1.1",

        "gray|1.1",

        "charcoal|1.1",

        "black|1.0"

);



my @sorted =  map  { $_->[0] }

              sort  { $b->[2] <=> $a->[2] || $a->[1] cmp $b->[1] }

              map  { [ $_,  split /\|/ ] } @arr_data;

  

foreach my $line (@sorted) {

  print "\t$line\n";

}

This uses the Schwartzian transform.

the true way of unix would be:

/bin/sort -t\| -k2,3n -k1,2 < list

Whoa - a perl thread that bigearsbilly refuses to answer.
What's the world coming to ???.

ho ho!

as a true perl (zeal|big)ot and officianado
even I would go for the path of least typing on this one.

;)

unless of course maybe the individual is
unfortunate enough to be using perl on windows.

Quote:

Originally Posted by bigearsbilly (Post 3380897)

the true way of unix would be:

/bin/sort -t\| -k2,3n -k1,2 < list

Two things: first, the OP wanted the numeric sort to be reversed (this is easily fixed); second, how exactly do we know that this isn't part of a larger project that is in Perl for a good reason?

In any case, here is a fixed sort incantation:

Code:

sort -t\| -k2,3nr -k1,2 < unsorted

1. doh!
sort -k2,3rn -k1,2

2. I don't. Just opining :) Still it is best to use the power at your fingertips if you can.

bigearsbilly - I can't use sort (ie. not perl) because this is to be a part of a larger perl script I'm writing in which it all should be self-contained since I'm sorting data that is already loaded into the variables. I was trying to right a sort function for including in the script I'm working on.

Telemachos - Your Schwartzian transform code example is what I'll go with. Thank you. :)