Reference+

#### Name

### atan2()

#### Description

Calculates the angle (in radians) from a specified point to the
coordinate origin as measured from the positive x-axis. Values are
returned as a **float** in the range from **PI** to **-PI**.
The **atan2()** function is most often used for orienting geometry to
the position of the cursor. Note: The y-coordinate of the point is the
first parameter and the x-coordinate is the second due the structure
of calculating the tangent.

#### Examples

`void draw() { background(204); translate(width/2, height/2); float a = atan2(mouseY-height/2, mouseX-width/2); rotate(a); rect(-30, -5, 60, 10); }`

#### Syntax

`atan2(y, x)`

#### Parameters

`y`

`(float)`

y-coordinate of the point`x`

`(float)`

x-coordinate of the point

#### Return

`float`

#### Related

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