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Re: Calculation of the time overlapping

by Anonymous Monk
on Mar 25, 2012 at 14:05 UTC ( #961482=note: print w/ replies, xml ) Need Help??


in reply to Calculation of the time overlapping

Your problem starts here

my @arr_b = grep { $_ % 3600 == 0 } ($start_b .. $end_b); my @arr_a = grep { $_ % 3600 == 0 } ($start_a .. $end_a);

Sure, I hate to do math too, esp the fuzzy date math, but DateTime::Span already does the math for us :) no need to generate ranges like some ruby programmer :)

With my modification I get 5 second speedup

$ perl -s timeoverlap.961234.pl Start: Sun Mar 25 06:53:28 2012 Start: 0 unit6;449 unit2;1014 End: Sun Mar 25 06:53:34 2012 End: 6 $ perl -s timeoverlap.961234.pl -withDateTime Start: Sun Mar 25 06:53:37 2012 Start: 1 unit6;447 unit2;1013 End: Sun Mar 25 06:53:37 2012 End: 1

Sure my numbers don't exactly match yours but they're close enough :) maybe even more correct; here is my modification, add it to your program after split

use vars qw/ $withDateTime /; if( $withDateTime ){ use if $withDateTime,qw/ DateTime::Span /; use if $withDateTime,qw/ DateTime::Format::Strptime /; #~ use DateTime::Span; #~ use DateTime::Format::Strptime; my $strp = DateTime::Format::Strptime->new( #~ 29.10.2008 13:00:00 #~ %d.%m.%Y %T pattern => '%d.%m.%Y %T', ); my $span_a = DateTime::Span->from_datetimes( start => $strp->parse_datetime($start_a_str), end => $strp->parse_datetime($end_a_str), ); my $span_b = DateTime::Span->from_datetimes( start => $strp->parse_datetime($start_b_str), end => $strp->parse_datetime($end_b_str), ); my $set = $span_a->intersection( $span_b ); my $dur = $set->duration; my $thours = 0; $thours += $dur ->years *365*24; $thours += $dur ->months *30*24; $thours += $dur ->weeks *7*24; $thours += $dur ->days *24; $thours += $dur ->hours ; $thours += $dur ->minutes / 60 ; $thours += $dur ->seconds / 60 / 60 ; # irrelevant $thours = sprintf '%.f', $thours; # round $hash{$wds} += $thours if $thours; next STRING; }

And sure, DateTime::Duration is annoying and could have used some kind of  total_as_hours but it sure beats ranges :)


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Re^2: Calculation of the time overlapping
by vagabonding electron (Hermit) on Mar 27, 2012 at 18:33 UTC
    Thank you very much, this sounds encouraging !
    Unfortunately my ActiveState installation bites me again.
    There is no DateTime::Span module there available, only DateTime::Span::Common. If I start with DateTime::Span::Common (just a use declaration to test) it dies "Can't locate DateTime/Span.pm in @INC ..."
    Trying to install with cpan from the command line brings an error message
    "Warning: Cannot install DataTime::span, don't know what it is. Try the command i /DataTime::span/ to find objects with matching identifiers.
    There is not DateTime::Duration module, only Datetime::Duration::Fuzzy.
    :-( Update: Sorry! There is DataTime::Duration there, sorry, I have used the false script.

        Thank you very much!

        The link to the ppm repository and the hint that DateTime::Span is in the DateTime::Set distribution did it!
        Now have run the new script - in fact your script - against the "real life" data from the first post.
        Start: Tue Mar 27 21:12:58 2012 End: Tue Mar 27 21:13:34 2012
        That means over 15 times faster!
        Many many thanks again!
        VE

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