# 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 parameter, due the the structure of calculating the tangent.

# Related

# Example

##### Code:

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); }