/*************************************************************************
 *  Compilation:  javac Point.java
 *  Execution:    java Point
 *
 *  Implementation of 2D point using rectangular coordinates.
 *
 *************************************************************************/

import java.awt.Color;

class Point { 
   private double x;
   private double y; 
   
   public Point() { x = Math.random(); y = Math.random(); }

   public Point(double x, double y) { this.x = x; this.y = y; }

   public double x() { return x; }
   public double y() { return y; }
   public double r() { return Math.sqrt(x*x + y*y); }
   public double theta() { return Math.atan2(y, x); }

   public double dist(Point p) {
      double dx = this.x() - p.x();
      double dy = this.y() - p.y();
      return Math.sqrt(dx*dx + dy*dy);
   }

   public Point avg(Point p) {
      return new Point((x + p.x) / 2, (y + p.y) / 2);
   }

   public String toString() { return "(" + x + ", " + y + ")"; } 



   // test client
   public static void main(String[] args) {
      Point p = new Point();
      System.out.println("p  = " + p);
      System.out.println("   x     = " + p.x());
      System.out.println("   y     = " + p.y());
      System.out.println("   r     = " + p.r());
      System.out.println("   theta = " + p.theta());
      System.out.println();

      Point q = new Point(0.5, 0.5);
      System.out.println("q  = " + q);
      System.out.println("dist(p, q) = " + p.dist(q) + " = " + q.dist(p));
   }
}