1 package org.lcsim.recon.vertexing.billoir;
2 /**
3 * @version $Id: Vertex.java,v 1.2 2006/03/28 23:50:27 jstrube Exp $
4 */
5 //Testing...
6 // A class encapsulating the behavior of a vertex constructed
7 // from tracks. It is written to be independent of any other
8 // packages and therefore makes extensive use of arrays and
9 // internal methods. It is not object-oriented in any way.
10 // But it should work.
11 //
12 public class Vertex {
13 public int _ntrk; // the number of tracks used in this fit
14 public double[] _xyzf; // the vertex position in Cartesian coordinates
15 public double[] _vcov; // packed covariance matrix on _xyzf
16
17 public double[][] _parf; // the fitted parameters at the vertex
18 // 0: theta
19 // 1: phi
20 // 2: 1/R
21 public double[][] _tcov; // covariance matrix on _parf
22
23 public double _chi2; // chisquared of vertex fit;
24 public double[] _chi2tr; // chisquared contribution of each track
25
26 // default constructor
27 public Vertex() {
28 _ntrk = 0;
29 _xyzf = new double[3];
30 _parf = new double[3][0];
31 _vcov = new double[6];
32 _tcov = new double[6][0];
33 _chi2 = 0.;
34 _chi2tr = new double[0];
35 }
36
37 // constructor
38 public Vertex(int ntrk, double[] xyz, double[][] parf, double[] vcov, double[][] tcov, double chi2, double[] chi2tr) {
39 _ntrk = ntrk;
40 _xyzf = xyz;
41 _parf = parf;
42 _vcov = vcov;
43 _tcov = tcov;
44 _chi2 = chi2;
45 _chi2tr = chi2tr;
46 }
47
48 public String toString() {
49 StringBuffer sb = new StringBuffer("Vertex at : \nx= "
50 + _xyzf[0]
51 + " +/- "
52 + Math.sqrt(_vcov[0])
53 + "\ny= "
54 + _xyzf[1]
55 + " +/- "
56 + Math.sqrt(_vcov[2])
57 + "\nz= "
58 + _xyzf[2]
59 + " +/- "
60 + Math.sqrt(_vcov[5])
61 + "\nchi2 = "
62 + _chi2);
63 for (int i = 0; i < _ntrk; ++i) {
64 sb.append("\n chi2[" + i + "]= " + _chi2tr[i]);
65 }
66 return sb.toString();
67
68 }
69
70 }