in reply to Re: Need help comparing 4 dates (sort errors?)
in thread Need help comparing 4 dates

It populates an array with the dates; sorts the indices of the array, by the (ascending) values of the dates indexed; then adds one to the ordered indices to produce your "ranking value".

But the 'ranking value' is really the date itself: the earliest date is 'first place', the latest date is 'fourth place' (in the OPed example data). It's necessary to convert each date, at some point, into its 'place' from 1 to n.

Once the ordered dates have been converted to place values, they have to be restored to the original order of the 'players' Jim .. Jack for printing.

  • Comment on Re^2: Need help comparing 4 dates (sort errors?)

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Re^3: Need help comparing 4 dates (Fixed.)
by BrowserUk (Patriarch) on Oct 03, 2010 at 10:31 UTC

    Duh! Of course. Thanks.

    Once I've sorted the indices by the dates, in order to rank them; I need to sort the indices by that ranking to get them back into the original order: 

    #! perl -slw
use warnings;
use strict;
use Data::Dumper;
use Date::Manip;

print scalar <DATA>;
while (<DATA>) {
    chomp;
    my @dates = split '~';
    my $label = shift @dates;
    my @order = sort{
        Date_Cmp( $dates[ $a ], $dates[ $b ] );
    } 0 .. $#dates;

    print join "\t", $label, map $_+1, sort{
        $order[ $a ] <=> $order[ $b ]
    } 0..$#order;
}

__DATA__
EVENT   JIM     BOB     SAM     JACK
PTRED~09/29/10 03:23:05 PM ~09/28/10 02:21:09 PM ~09/26/10 11:00:03 AM
+ ~09/27/10 09:33:41 PM
RED~08/29/10 01:55:00 AM ~08/30/09 12:10:10 PM ~08/27/10 08:16:21 PM ~
+09/01/10 12:12:12 AM
INT~07/04/10 03:21:15 AM ~07/08/10 04:17:33 PM ~06/30/10 04:22:11 AM ~
+06/28/10 10:11:01 PM
PTRED~06/19/10 09:19:55 PM ~04/25/10 07:39:22 PM ~09/16/10 10:34:24 AM
+ ~07/22/10 06:19:38 PM
RED~04/29/10 12:10:59 AM ~04/20/10 02:13:33 AM ~07/17/10 01:00:05 PM ~
+09/01/10 11:10:15 PM
INT~05/23/10 11:11:11 PM ~01/08/10 10:45:12 PM ~05/15/09 03:29:37 AM ~
+05/18/09 12:59:59 PM

    [download]

    Produces:

    c:\test>junk51
EVENT   JIM     BOB     SAM     JACK

PTRED   4       3       1       2
RED     3       1       2       4
INT     3       4       2       1
PTRED   2       1       4       3
RED     2       1       3       4
INT     4       3       1       2

    [download]
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      Thank you so much! This is spot on!

[reply]

      Hi All, this does work beautifully, except for one thing...i keep getting the following warning message:

      Use of uninitialized value in length at /u/capsftp/lib/perl5/site_perl/5.8.0/Date/Manip.pm line 247, <DATA> line 2

      I was curious if you were getting it also? and if so, any idea what is causing it? With Data::Dumper i can see the values all seem to be defined when passed to the Date_Cmp function so not sure why it's happening

[reply]

        Have you by any chance got a blank line after the headers and before the dates?

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