From AutoIt Wiki

Calculates the arctangent of a number. Adapted from AutoIt docs.

Contents 1 Syntax 2 Parameters 3 Return Value 4 Example

Syntax

$x = ATan(expr)

Parameters

expr	Any valid numeric expression

Return Value

Returns the trigonometric arctangent of expr. Result is in radians.

Example

$pi = 4 * ATan(1) ; equal to 3.14159265358979
$radToDeg = 180 / $pi
$y = ATan(1) * $radToDeg ; arctangent of 1 returns 45 deg