1 package org.lcsim.recon.tracking.spacegeom;
2
3 import java.io.PrintStream;
4
5 class Eigensystem
6 {
7
8 protected Matrix _eigenvalue;
9 protected Matrix _eigenvector;
10 protected int _index[];
11
12 public Eigensystem()
13 {
14 }
15
16 public void eigensort()
17 {
18 if(_eigenvalue == null)
19 {
20 System.err.println("Eigensystem::eigensort - No eigenvalues to sort.");
21 System.exit(0);
22 }
23 if(_eigenvector == null)
24 {
25 System.err.println("Eigensystem::eigensort - No eigenvectors to sort.");
26 System.exit(0);
27 }
28 int j1 = _eigenvalue.rows();
29 _index = new int[j1];
30 for(int i = 0; i < j1; i++)
31 _index[i] = i;
32
33 for(int j = 0; j < j1 - 1; j++)
34 {
35 int i1 = j;
36 double d = _eigenvalue.at(i1, 0);
37 for(int k = j + 1; k < j1; k++)
38 if(_eigenvalue.at(k, 0) >= d)
39 {
40 i1 = k;
41 d = _eigenvalue.at(i1, 0);
42 }
43
44 if(i1 != j)
45 {
46 int k1 = _index[i1];
47 _index[i1] = _index[j];
48 _index[j] = k1;
49 _eigenvalue.set(i1, 0, _eigenvalue.at(j, 0));
50 _eigenvalue.set(j, 0, d);
51 for(int l = 0; l < j1; l++)
52 {
53 double d1 = _eigenvector.at(l, j);
54 _eigenvector.set(l, j, _eigenvector.at(l, i1));
55 _eigenvector.set(l, i1, d1);
56 }
57
58 }
59 }
60
61 }
62
63 public double eigenvalue(int i)
64 {
65 if(_eigenvalue == null)
66 {
67 System.err.println("Eigensystem::getEigenvalue - No vector of eigenvalues availible.");
68 System.exit(0);
69 }
70 int j = _eigenvalue.rows();
71 if(i > j - 1 || i < 0)
72 {
73 System.err.println("Eigensystem::getEigenvalue - Invalid index specified.");
74 System.exit(0);
75 }
76 return _eigenvalue.at(i, 0);
77 }
78
79 public Matrix eigenvalues()
80 {
81 return _eigenvalue;
82 }
83
84 public Matrix eigenvector(int i)
85 {
86 if(_eigenvector == null)
87 {
88 System.err.println("Eigensystem::getEigenvector - No matrix of eigenvectors availible.");
89 System.exit(0);
90 }
91 int j = _eigenvalue.rows();
92 if(i > j - 1 || i < 0)
93 {
94 System.err.println("Eigensystem::getEigenvector - Invalid index specified.");
95 System.exit(0);
96 }
97 Matrix matrix = _eigenvector.submatrix(j, 1, 0, i);
98 return matrix;
99 }
100
101 public Matrix eigenvectors()
102 {
103 return _eigenvector;
104 }
105
106 public int[] index()
107 {
108 return _index;
109 }
110
111 public void setEigenvalues(Matrix matrix)
112 {
113 if(matrix.cols() != 1)
114 {
115 System.err.println("Eigensystem::setEigenvalues -> Invalid dimension.");
116 System.exit(0);
117 }
118 _eigenvalue = matrix;
119 }
120
121 public void setEigenvectors(Matrix matrix)
122 {
123 _eigenvector = matrix;
124 }
125
126 public void setIndex(int ai[])
127 {
128 _index = ai;
129 }
130 }