atan2 Y,X
Returns the arctangent of Y/X in the range -PI to PI.
For the tangent operation, you may use the Math::Trig::tan
function, or use the familiar relation:
sub tan { sin($_[0]) / cos($_[0]) }
The return value for atan2(0,0)
is implementation-defined; consult your atan2(3) manpage for more information.
Portability issues: atan2 in perlport.
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