本程序未優化，比較好的方法是，進行曲線積分，算誤差比進行方程約束，由于時間比較少，稍候會給出優化程序。
1 package com.ibm.nicky.PLR;
2
3 /**
4 * @author Qu Qiang
5 *
6 */
7 public class PLR {
8 public static final double LIMIT = 0.09;
9
10 PLR() {
11 }
12
13 /**
14 * @param args
15 */
16 public static void main(String[] args) {
17
18 Point[] parray = { new Point(3, 5), new Point(4, 6), new Point(5, 6),
19 new Point(6, 6.8), new Point(7, 7.9) };
20 int temp = 0;
21 double max = 0.0;
22 double x1 = parray[0].getX();
23 double y1 = parray[0].getY();
24 double x2 = parray[parray.length - 1].getX();
25 double y2 = parray[parray.length - 1].getY();
26 double y1my2 = y1 - y2;
27 double x2mx2 = x2 - x1;
28 double C = y2 * x1 - y1 * x2;
29 double length = Math.sqrt(Math.pow((double) (y2 - y1), 2.0)
30 + Math.pow((double) (x2 - x1), 2.0));
31 System.out.println(length);
32 double d[] = new double[10];
33 for (int i = 1; i < parray.length - 1; i++) {
34
35 double x = parray[i].getX();
36 double y = parray[i].getY();
37
38 d[i] = Math.abs(x * y1my2 + y * x2mx2 + C) / length;
39 }
40 for (int i = 1; i < parray.length - 1; i++) {
41 max = d[1];
42 if (d[i] > max) {
43 max = d[i];
44 temp = i;
45 }
46 }
47 if (max >= LIMIT) {
48 System.out.println("this point x=" + parray[temp].getX()
49 + " is the target point");
50 }
51 double k1 = (parray[temp].getY() - y1) / (parray[temp].getX() - x1);
52 double k2 = (y2 - parray[temp].getY()) / (x2 - parray[temp].getX());
53 double b1 = y1 - k1 * x1;
54 double b2 = y2 - k2 * x2;
55 System.out.println("the first line is y=" + k1 + "x+" + b1);
56 System.out.println("the second line is y=" + k2 + "x+" + b2);
57 }
58 }
1 package com.ibm.nicky.plr;
2
3 /**
4 * @author Qu Qiang
5 *
6 */
7
8 public class Point {
9
10 private double x;
11 private double y;
12 Point(double x,double y){
13 this.x=x;
14 this.y=y;
15 }
16 public double getX(){return this.x;}
17 public double getY(){return this.y;}
18 }
19
http://www.gotoread.com/s/e/?vo=1858&p=60
posted on 2007-08-14 17:27
wqwqwqwqwq 閱讀(1006)
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Data Structure && Algorithm