001package algs12;
002import  stdlib.*;
003
004/* ***********************************************************************
005 *  Compilation:  javac Interval2D.java
006 *  Execution:    java Interval2D
007 *
008 *  2-dimensional interval data type.
009 *
010 *************************************************************************/
011
012public class Interval2D {
013        private final Interval1D x;
014        private final Interval1D y;
015
016        public Interval2D(Interval1D x, Interval1D y) {
017                this.x = x;
018                this.y = y;
019        }
020
021        // does this interval intersect that one?
022        public boolean intersects(Interval2D that) {
023                if (!this.x.intersects(that.x)) return false;
024                if (!this.y.intersects(that.y)) return false;
025                return true;
026        }
027
028        // does this interval contain x?
029        public boolean contains(Point2D p) {
030                return x.contains(p.x())  && y.contains(p.y());
031        }
032
033        // area of this interval
034        public double area() {
035                return x.length() * y.length();
036        }
037
038        public String toString() {
039                return x + " x " + y;
040        }
041
042        public void draw() {
043                double xc = (x.left() + x.right()) / 2.0;
044                double yc = (y.left() + y.right()) / 2.0;
045                StdDraw.rectangle(xc, yc, x.length() / 2.0, y.length() / 2.0);
046        }
047
048        // test client
049        public static void main(String[] args) {
050                args = new String[] { ".3", ".4", ".5", ".6", "1000" };
051
052                double xlo = Double.parseDouble(args[0]);
053                double xhi = Double.parseDouble(args[1]);
054                double ylo = Double.parseDouble(args[2]);
055                double yhi = Double.parseDouble(args[3]);
056                int T = Integer.parseInt(args[4]);
057
058                Interval1D xinterval = new Interval1D(xlo, xhi);
059                Interval1D yinterval = new Interval1D(ylo, yhi);
060                Interval2D box = new Interval2D(xinterval, yinterval);
061                box.draw();
062
063                Counter counter = new Counter("hits");
064                for (int t = 0; t < T; t++) {
065                        double x = StdRandom.random();
066                        double y = StdRandom.random();
067                        Point2D p = new Point2D(x, y);
068
069                        if (box.contains(p)) counter.increment();
070                        else                 p.draw();
071                }
072
073                StdOut.println(counter);
074                StdOut.format("box area = %.2f\n", box.area());
075        }
076}