Reference for Processing version 1.5. If you have a previous version, use the reference included with your software. If you see any errors or have suggestions, please let us know.
		If you prefer a more technical reference, visit the Processing Javadoc.
	
		| Name | atan2() | 
	
		| Examples | void draw() {
  background(204);
  translate(width/2, height/2);
  float a = atan2(mouseY-height/2, mouseX-width/2);
  rotate(a);
  rect(-12, -5, 24, 10);
} | 
	
		| 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 the structure of calculating the tangent. | 
	
		| Syntax | atan2(y, x); | 
	
		| Parameters | 
	
		| y | int or float: y-coordinate of the point |  
		| x | int or float: x-coordinate of the point |  | 
	
		| Returns | float | 
	
		| Usage | Web & Application | 
	
		| Related | tan() 
 | 
Updated on August 30, 2010 04:29:39pm EDT