1 package org.lcsim.event;
2
3 /**
4 * The LCIO TrackState interface.
5 *
6 * @author gaede, engels
7 * @author Jeremy McCormick
8 * @version $Id: TrackState.java,v 1.2 2012/06/18 23:02:14 jeremy Exp $
9 */
10 public interface TrackState
11 {
12 // TrackState location codes.
13 public final static int AtOther = 0; // Any location other than the ones defined below.
14 public final static int AtIP = 1;
15 public final static int AtFirstHit = 2;
16 public final static int AtLastHit = 3;
17 public final static int AtCalorimeter = 4;
18 public final static int AtVertex = 5;
19 public final static int LastLocation = AtVertex;
20
21 /**
22 * The location of the track state.
23 * Location can be set to: AtIP, AtFirstHit, AtLastHit, AtCalorimeter, AtVertex, AtOther
24 */
25 public int getLocation();
26
27 /**
28 * Impact paramter of the track in (r-phi).
29 */
30 public double getD0();
31
32 /**
33 * Phi of the track at the reference point.
34 * @see getReferencePoint
35 */
36 public double getPhi();
37
38 /**
39 * Omega is the signed curvature of the track in [1/mm].
40 * The sign is that of the particle's charge.
41 */
42 public double getOmega();
43
44 /**
45 * Impact paramter of the track in (r-z).
46 */
47 public double getZ0();
48
49 /**
50 * Lambda is the dip angle of the track in r-z at the reference point.
51 * @see getReferencePoint
52 */
53 public double getTanLambda();
54
55 /**
56 * Get the ordered list of 5 LCIO track parameters.
57 * @return The track parameters as a double array of size 5.
58 */
59 public double[] getParameters();
60
61 /**
62 * Covariance matrix of the track parameters. Stored as lower triangle matrix where
63 * the order of parameters is: d0, phi, omega, z0, tan(lambda).
64 * So we have cov(d0,d0), cov( phi, d0 ), cov( phi, phi), ...
65 * @return A double array of size 15 containing the covariance matrix of the track parameters.
66 */
67 public double[] getCovMatrix();
68
69 /**
70 * Reference point of the track parameters.
71 * The default for the reference point is the point of closest approach.
72 * @return The reference point of the track parameters as a double array of size 3.
73 */
74 public double[] getReferencePoint();
75
76 public double[] getMomentum();
77
78 /**
79 * Get an individual track parameter.
80 * They are returned by the following keys:
81 * 0 = d0
82 * 1 = phi
83 * 2 = omega
84 * 3 = z0
85 * 4 = tanLambda
86 * This order is defined in BaseTrack.
87 * @return The track parameters.
88 */
89 public double getParameter(int iparam);
90 }