http://www.perlmonks.org?node_id=654278


in reply to Best Material for Floors:

Come on everyone, why use something so complicated. If you need floor just use POSIX! It comes standard with all perls (I think).

Ted Young

($$<<$$=>$$<=>$$<=$$>>$$) always returns 1. :-)

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Re^2: Best Material for Floors: (POSIX--)
by tye (Sage) on Dec 01, 2007 at 05:32 UTC

    Bleh. POSIX::floor() on a Perl that uses "long double" (or similar) as NVs induces a great reduction in precision. Much better to just use:

    sub floor { $_[0] < 0 ? -int(-$_[0]) : int($_[0]); }
    sub floor { my $i= int( my $f= shift @_ ); return $i - ( $f<0 && $f!=$ +i ); }

    Now you know. :)

    - tye        

      floor -2.5 Should return -3.

        Heh, thanks. Fixed. Since I discovered the problem working with really large numbers, even my previous version was tons more accurate than POSIX::floor in that particular situation so it fixed the problem. That's how bad POSIX::floor can be.

        - tye