# Atan2

## Description

The atan2 function is a variation of the atan function. For a given coordinates $(x, y)$, $atan2(y, x)$ is the angle between the positive X axis and the point $(x, y)$. The angle is positive for counter-clockwise angles (where $y > 0$), and negative for clockwise angles (where $y < 0$). The result angle range is $(-\pi , \pi ]$, and for both x and y are zeroes, $atan2(0, 0) = 0$.

Returned values are in radians, degrees or gradians, depending upon the system.math.angularunits object property (which can also be set in the Options dialog box).

## Syntax

double Atan2(double y, double x)

## Parameters

y

The y value of coordinate $(x, y)$.

x

The x value of coordinate $(x, y)$.

## Return

Return the angle between the positive X axis and the point given by the coordinates $(x, y)$.

## Example

atan2(4, 3) = ;  // 0.92729521800161
atan2(0, -1) = ;  // 3.1415926535898
atan2(0, 0) = ;  // 0
atan2(-1, -1) = ;  // -2.3561944901923