1 /*
2 * HelicalTrack3DHit.java
3 *
4 * Created on November 13, 2007, 12:39 PM
5 *
6 */
7
8 package org.lcsim.fit.helicaltrack;
9
10 import hep.physics.vec.Hep3Vector;
11 import hep.physics.matrix.SymmetricMatrix;
12 import hep.physics.vec.BasicHep3Vector;
13
14 import java.util.List;
15
16 import org.lcsim.geometry.subdetector.BarrelEndcapFlag;
17
18 /**
19 * Encapsulate 3D hit info needed by HelicalTrackFitter. Pixel hits should be
20 * instantiated using this class. The BarrelEndcapFlag determines whether the
21 * the measurement coordinates are taken to be r*phi and z (barrel) or r*phi
22 * and r (endcap disk).
23 * @author Richard Partridge
24 * @version 1.0
25 */
26 public class HelicalTrack3DHit extends HelicalTrackHit {
27 private double _dz;
28 private static int _type = 1;
29
30 public HelicalTrack3DHit(Hep3Vector pos, SymmetricMatrix cov, double dEdx, double time,
31 List rawhits, String detname, int layer, BarrelEndcapFlag beflag) {
32 super(pos, cov, dEdx, time, _type, rawhits, detname, layer, beflag);
33 _dz = Math.sqrt(cov.e(2, 2));
34 if (! (_dz>_eps)) //_eps inherited from HelicalTrackHit
35 _dz = _eps;
36 }
37
38 /**
39 * Create a HelicalTrack3DHit from a TrackerHit.
40 * @param hit TrackerHit associated with this hit
41 * @param beflag BarrelEndcapFlag for this hit
42 */
43 // public HelicalTrack3DHit(TrackerHit hit, BarrelEndcapFlag beflag) {
44 // super(hit);
45 // super.setBarrelEndcapFlag(beflag);
46 // _dz = Math.sqrt(hit.getCovMatrix()[5]);
47 // }
48
49 /**
50 * Create a HelicalTrack3DHit from a TrackerHit overriding the hit position
51 * and covariance matrix in the TrackerHit.
52 * @param hit TrackerHit associated with this hit
53 * @param pos hit position
54 * @param cov covariance matrix
55 * @param beflag BarrelEndcapFlag for this hit
56 */
57 // public HelicalTrack3DHit(TrackerHit hit, Hep3Vector pos, SymmetricMatrix cov, BarrelEndcapFlag beflag) {
58 // super(hit, pos, cov);
59 // super.setBarrelEndcapFlag(beflag);
60 // _dz = Math.sqrt(cov.e(2,2));
61 // }
62
63 /**
64 * Create a HelicalTrack3DHit from scratch without reference to an existing
65 * TrackerHit. The BarrelEndcapFlag defaults to barrel, but can be set to
66 * an endcap disk using the parent method setBarrelEndcapFlag.
67 * @param x x coordinate
68 * @param y y coordinate
69 * @param z z coordinate
70 * @param drphi uncertainty in the r*phi coordinate
71 * @param dz uncertainty in the z coordinate
72 */
73 @Deprecated
74 public HelicalTrack3DHit(double x, double y, double z, double drphi, double dz){
75 this(new BasicHep3Vector(x, y, z), HitUtils.PixelCov(x, y, drphi, dz), 0., 0., null,
76 "Unknown", 0 , BarrelEndcapFlag.BARREL);
77 _dz = dz;
78 }
79
80 /**
81 * Return the uncertainty in the z coordinate.
82 * @return uncertainty in the z coordinate
83 */
84 public double dz() {
85 if (super.BarrelEndcapFlag() == BarrelEndcapFlag.BARREL) return _dz;
86 else throw new RuntimeException("z coordinate uncertainty undefined for a disk hit");
87 }
88 }
89