1 package org.lcsim.recon.tracking.trfxyp;
2
3 import org.lcsim.recon.tracking.trfutil.Assert;
4
5 import org.lcsim.recon.tracking.trfbase.Hit;
6 import org.lcsim.recon.tracking.trfbase.HitVector;
7 import org.lcsim.recon.tracking.trfbase.HitError;
8 import org.lcsim.recon.tracking.trfbase.HitDerivative;
9 import org.lcsim.recon.tracking.trfbase.ETrack;
10 import org.lcsim.recon.tracking.trfbase.TrackVector;
11 import org.lcsim.recon.tracking.trfbase.TrackError;
12 /**
13 * Describes a two dimensional (v,z) measurement on an XYPlane.
14 *<p>
15 * This is a very simple hit. It produces one prediction with fixed
16 * measurement which is simply the (v,z) of the track.
17 *
18 *@author Norman A. Graf
19 *@version 1.0
20 *
21 */
22 //cng changed to public for component tests
23 public class HitXYPlane2 extends Hit
24 {
25
26 // Only ClusXYPlane2 is allowed to construct HitXYPlane2 objects.
27 // package protection
28
29 // store the HitDerivative
30 private static double values[] =
31 { 1.0, 0.0, 0.0, 0.0, 0.0,
32 0.0, 1.0, 0.0, 0.0, 0.0 };
33 private static HitDerivative _deriv = new HitDerivative(2,values);
34
35 /**
36 *Return a String representation of the class' type name.
37 *Included for completeness with the C++ version.
38 *
39 * @return A String representation of the class' type name.
40 */
41 public static String typeName()
42 { return "HitXYPlane2"; }
43
44 /**
45 *Return a String representation of the class' type name.
46 *Included for completeness with the C++ version.
47 *
48 * @return A String representation of the class' type name.
49 */
50 public static String staticType()
51 { return typeName(); }
52
53 // prediction for hm
54 private double _v;
55 private double _z;
56
57 // error matrix for hm
58 private double _dv2;
59 private double _dz2;
60 private double _dvdz;
61
62
63 // equality
64 // Hits are equal if they have the same parent cluster.
65 protected boolean equal( Hit hit)
66 {
67 Assert.assertTrue( type().equals(hit.type()) );
68 return cluster().equals(hit.cluster());
69 }
70
71 // constructor
72 HitXYPlane2(double v, double z, double dv2, double dz2, double dvdz)
73 {
74 _v = v;
75 _z = z;
76 _dv2 = dv2;
77 _dz2 = dz2;
78 _dvdz = dvdz;
79 }
80
81 /**
82 *Construct an instance replicating the HitXYPlane2 ( copy constructor ).
83 *
84 * @param hit The Hit to replicate.
85 */
86 public HitXYPlane2( HitXYPlane2 hit)
87 {
88 super(hit);
89 _v = hit._v;
90 _z = hit._z;
91 _dv2 = hit._dv2;
92 _dz2 = hit._dz2;
93 _dvdz = hit._dvdz;
94 }
95
96 /**
97 *Return the dimension of a (v,z) measurement on an xy plane.
98 *The value is always two.
99 *
100 * @return The dimension of this hit (2).
101 */
102 public int size()
103 { return 2; }
104
105 /**
106 *Return the measured hit vector.
107 *
108 * @return The HitVector for this hit.
109 */
110 public HitVector measuredVector()
111 {
112 ClusXYPlane2 clu = fullCluster();
113 return new HitVector( clu.v(), clu.z() );
114 }
115
116 /**
117 *Return the measured hit error.
118 *
119 * @return The HitError for this hit.
120 */
121 public HitError measuredError()
122 {
123 ClusXYPlane2 clu = fullCluster();
124 return new HitError(clu.dV2(),clu.dVdZ(), clu.dZ2() );
125 }
126
127 /**
128 *Return the predicted hit vector.
129 *
130 * @return The HitVector for the prediction.
131 */
132 public HitVector predictedVector()
133 {
134 return new HitVector( _v, _z );
135 }
136
137 /**
138 *Return the predicted hit error.
139 *
140 * @return The HitError for the prediction.
141 */
142 public HitError predictedError()
143 {
144 return new HitError( _dv2,_dvdz,_dz2 );
145 }
146
147 /**
148 *Return the hit derivative with respect to a track on this surface.
149 *
150 * @return The HitDerivative for a track on this surface.
151 */
152 public HitDerivative dHitdTrack()
153 {
154 return _deriv;
155 }
156
157 /**
158 *Return the difference between prediction and measurement.
159 *
160 * @return The HitVector for the difference between the hit prediction and measurement.
161 */
162 public HitVector differenceVector()
163 {
164
165 ClusXYPlane2 clu = fullCluster();
166
167
168 double diff_v = _v - clu.v();
169 double diff_z = _z - clu.z();
170 return new HitVector( diff_v, diff_z );
171 }
172
173 /**
174 *Update the prediction (measurement and derivative do not change).
175 *
176 * @param tre The ETrack for which to predict this hit measurement.
177 */
178 public void update( ETrack tre)
179 {
180 TrackVector vec = tre.vector();
181
182 _v = vec.get(SurfXYPlane.IV);
183 _z = vec.get(SurfXYPlane.IZ);
184
185 TrackError err = tre.error() ;
186
187 _dv2 = err.get(SurfXYPlane.IV,SurfXYPlane.IV);
188 _dvdz = err.get(SurfXYPlane.IV,SurfXYPlane.IZ);
189 _dz2 = err.get(SurfXYPlane.IZ,SurfXYPlane.IZ);
190
191 }
192
193 /**
194 *Return a ClusXYPlane2 reference to the cluster.
195 *
196 * @return The hit as a ClusXYPlane2 object.
197 */
198 public ClusXYPlane2 fullCluster()
199 { return ( ClusXYPlane2) _pclus; }
200
201 /**
202 * Return the measured v position of the hit.
203 *
204 * @return The measured v position of the hit.
205 */
206 public double v()
207 { return _v; }
208 /**
209 * Return the measured z position of the hit.
210 *
211 * @return The measured z position of the hit.
212 */
213 public double z()
214 { return _z; }
215 /**
216 * Return the error matrix term for v.
217 *
218 * @return The error matrix term for v.
219 */
220 public double dV2()
221 { return _dv2; }
222 /**
223 * Return the error matrix term for z.
224 *
225 * @return The error matrix term for z.
226 */
227 public double dZ2()
228 { return _dz2; }
229 /**
230 * Return the error matrix covariance term.
231 *
232 * @return The error matrix covariance term.
233 */
234 public double dVdZ()
235 { return _dvdz; }
236
237 /**
238 *Return a String representation of the class' type name.
239 *Included for completeness with the C++ version.
240 *
241 * @return A String representation of the class' type name.
242 */
243 public String type()
244 { return staticType(); };
245
246 /**
247 *output stream
248 *
249 * @return A String representation of this instance.
250 */
251 public String toString()
252 {
253 if ( _pclus != null )
254 {
255 return "HitXYPlane2 prediction for " +_pclus;
256 }
257 else return "HitXYPlane2 with no parent cluster.";
258 }
259
260 }