几何对象抽象数据类型

朱雀 2021-07-24 13:52 587阅读 0赞

**一 平面上的点API**

<table> 
 <tbody> 
 <tr> 
 <td colspan="2"> public class Point2D </td> 
 </tr> 
 <tr> 
 <td> public Point2D(double x, double y) </td> 
 <td> 创建一个点 </td> 
 </tr> 
 <tr> 
 <td> public double x() </td> 
 <td> x坐标 </td> 
 </tr> 
 <tr> 
 <td> public double&nbsp;y() </td> 
 <td> y坐标 </td> 
 </tr> 
 <tr> 
 <td> public double r() </td> 
 <td>极径（极坐标）</td> 
 </tr> 
 <tr> 
 <td> public double theta() </td> 
 <td> 极角（极坐标标） </td> 
 </tr> 
 <tr> 
 <td> public double distanceTo(Point2D that) </td> 
 <td> 从该点到that的欧几里得距离 </td> 
 </tr> 
 <tr> 
 <td> public void draw() </td> 
 <td> 用StdDraw绘出该点 </td> 
 </tr> 
 </tbody> 
</table>

**二 直线上的间隔API**

<table> 
 <tbody> 
 <tr> 
 <td colspan="2"> public&nbsp;class Interval1D </td> 
 </tr> 
 <tr> 
 <td> public Interval1D(double min, double max) </td> 
 <td> 创建一个间隔 </td> 
 </tr> 
 <tr> 
 <td> public double length() </td> 
 <td> 间隔长度 </td> 
 </tr> 
 <tr> 
 <td> public boolean contains(double x) </td> 
 <td> x是否在间隔中 </td> 
 </tr> 
 <tr> 
 <td> public boolean intersects(Interval1D that) </td> 
 <td> 该间隔是否和that间隔相交 </td> 
 </tr> 
 <tr> 
 <td> public void draw() </td> 
 <td> 用StdDraw绘出该间隔 </td> 
 </tr> 
 </tbody> 
</table>

**三 平面上的二维间隔API**

<table> 
 <tbody> 
 <tr> 
 <td colspan="2"> public&nbsp;class Interval2D </td> 
 </tr> 
 <tr> 
 <td> public Interval2D(Interval1D x, Interval1D y) </td> 
 <td> 创建一个二维间隔 </td> 
 </tr> 
 <tr> 
 <td> public double area() </td> 
 <td> 二维间隔的面积 </td> 
 </tr> 
 <tr> 
 <td> public boolean contains(Point2D p) </td> 
 <td> p是否在二维间隔中 </td> 
 </tr> 
 <tr> 
 <td> public boolean intersects(Interval2D that) </td> 
 <td> 该间隔是否和二维间隔that相交 </td> 
 </tr> 
 <tr> 
 <td> public void draw() </td> 
 <td> 用StdDraw绘出该二维间隔 </td> 
 </tr> 
 </tbody> 
</table>

**四 测试代码**

package MyDraw;
 
 import common.*;
 import Counter.*;
 import java.util.Arrays;
 
 /**
 * Copyright (C), 2020-2020, XXX有限公司
 * FileName: MyDraw
 * Author: cakin
 * Date: 2020/1/10
 * Description: 常用绘图
 */
 public class MyDraw {
 public static void main( String[] args ) {
 //drawFunc();
 //drawRandomAarray();
 //drawRandomSortedAarray();
 drawInterval2D(".2",".5",".5",".6","10000");
 }
 public static void drawInterval2D(String... args) {
 double xmin = Double.parseDouble(args[0]);
 double xmax = Double.parseDouble(args[1]);
 double ymin = Double.parseDouble(args[2]);
 double ymax = Double.parseDouble(args[3]);
 int trials = Integer.parseInt(args[4]);
 
 Interval1D xInterval = new Interval1D(xmin, xmax);
 Interval1D yInterval = new Interval1D(ymin, ymax);
 Interval2D box = new Interval2D(xInterval, yInterval);
 box.draw();
 
 Counter counter = new Counter("hits");
 for (int t = 0; t < trials; t++) {
 double x = StdRandom.uniform(0.0, 1.0);
 double y = StdRandom.uniform(0.0, 1.0);
 Point2D point = new Point2D(x, y);
 
 if (box.contains(point)) counter.increment();
 else point.draw();
 }
 
 StdOut.println(counter);
 StdOut.printf("box area = %.2f\n", box.area());
 }
 }

**五 测试结果**

![watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L2NoZW5ncWl1bWluZw_size_16_color_FFFFFF_t_70][]

**六 参考代码**

[https://gitee.com/cakin24/Algorithm][https_gitee.com_cakin24_Algorithm]

[watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L2NoZW5ncWl1bWluZw_size_16_color_FFFFFF_t_70]: /images/20210724/32a1d60e04a94103977735c78c5fe773.png
[https_gitee.com_cakin24_Algorithm]: https://gitee.com/cakin24/Algorithm/tree/master/src/main/java/MyMath