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

by AnomalousMonk (Canon)
on Oct 03, 2010 at 08:53 UTC ( #863157=note: print w/replies, xml ) Need Help??

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.

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Re^3: Need help comparing 4 dates (Fixed.)
by BrowserUk (Pope) 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


    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

    Examine what is said, not who speaks -- Silence betokens consent -- Love the truth but pardon error.
    "Science is about questioning the status quo. Questioning authority".
    In the absence of evidence, opinion is indistinguishable from prejudice.

      Thank you so much! This is spot on!

      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/ 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

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

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