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";