Perl Programming/Keywords/atan2

The atan2 keyword

atan2 is the trigonometric function tangent that returns the arctangent of Y/X in the range -π to π.

Syntax

 atan2 Y, X 

Examples

The code

*PI = \3.1415926535; $a = 3; $b = 5; $arctan = atan2($a, $b); print "arctan(" . $a . ", " . $b . ") = " . $arctan . " rad = " . $arctan*180/$PI . " deg\n"; 

prints the arc tangent in radians and degrees: