| Subject: | The method 'InnerAngle' sometimes returns a complex number. |
| Date: | Sun, 11 Mar 2007 18:54:04 +0000 |
| To: | bug-Math-Vec [...] rt.cpan.org |
| From: | "Barry Crabtree" <barry.crabtree [...] gmail.com> |
The method 'InnerAngle' sometimes returns a complex number. Seems to be when
the angle is about 180 degrees.
Math::Vec version 0.04
Perl: This is perl, v5.8.7 built for i486-linux-gnu-thread-multi
OS: Linux jitterbug 2.6.15-27-386 #1 PREEMPT Fri Dec 8 17:51:56 UTC 2006
i686 GNU/Linux
Reproduced with:
----------------------------------
#!/usr/bin/perl -w
use strict;
use Math::Vec;
my ($x1, $y1, $x2, $y2, $x3, $y3) = (184.818732905007, 1.88127517013888,
183.75578943, 1.9146946049724,
182.742125596, 1.94656466818785,
);
my $v1 = Math::Vec->new($x2-$x1, $y2-$y1);
my $v2 = Math::Vec->new($x2-$x3, $y2-$y3);
my $angle = $v1->InnerAngle($v2);
print "Angle is: $angle\n";
---------------------------------
prints: Angle is: 3.14159265358979-2.98023223876953e-08i
It seems to be more common on amd 64 bit machines (
http://lists.openstreetmap.org/pipermail/dev/2007-March/003380.html)
Hope this helps.
Cheers. Barry.
--
Live as if you were to die tomorrow. Learn as if you were to live
forever. - Gandhi.