public class Position {

	// Represent a position (radius, angle) in polar coordinates.
	// All angles are in radians.
	// The internal representation of an angle is always at least 0
	// and less than 2 * PI.  Also, the radius is always at least 1.
	
	public Position ( ) {
		myRadius = 0;
		myAngle = 0;
	}

	public Position (Position p) {
		myRadius = p.myRadius;
		myAngle = p.myAngle;
	}

	public Position (double r, double theta) {
		myRadius = r;
		myAngle = theta;
	}
	
	public int xCoord (int xCenter, int unit) {
		return xCenter + (int) (myRadius * Math.cos (myAngle) * unit);
	}
	
	public int yCoord (int yCenter, int unit) {
		return yCenter - (int) (myRadius * Math.sin (myAngle) * unit);
	}
	
	public String toString ( ) {
		return "(" + myRadius + "," + myAngle + ")";
	}
	
	// Update the current position either by changing myRadius
	// or by adding angularDistChange/myRadius to myAngle.
	// Preconditions: angularDistChange is less than 2 * PI and greater than -2 * PI;
	//   one of rChange and angularDistChange is 0.
	public void update (double rChange, double angularDistChange) {
		// You fill this in.
	}
	
	// You will also need other methods.
	
	private double myRadius;
	private double myAngle;
}