Added methods for finding a given module in the DDL map (F. Prino)
[u/mrichter/AliRoot.git] / STEER / AliTracker.cxx
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be9c5115 1/**************************************************************************
2 * Copyright(c) 1998-1999, ALICE Experiment at CERN, All rights reserved. *
3 * *
4 * Author: The ALICE Off-line Project. *
5 * Contributors are mentioned in the code where appropriate. *
6 * *
7 * Permission to use, copy, modify and distribute this software and its *
8 * documentation strictly for non-commercial purposes is hereby granted *
9 * without fee, provided that the above copyright notice appears in all *
10 * copies and that both the copyright notice and this permission notice *
11 * appear in the supporting documentation. The authors make no claims *
12 * about the suitability of this software for any purpose. It is *
13 * provided "as is" without express or implied warranty. *
14 **************************************************************************/
15
acd84897 16/* $Id$ */
fb17acd4 17
be9c5115 18//-------------------------------------------------------------------------
19// Implementation of the AliTracker class
9b83b8cc 20// that is the base for AliTPCtracker, AliITStrackerV2 and AliTRDtracker
21// Origin: Iouri Belikov, CERN, Jouri.Belikov@cern.ch
be9c5115 22//-------------------------------------------------------------------------
7d0f8548 23#include <TClass.h>
be9c5115 24#include <TMath.h>
e23a38cb 25#include <TH1F.h>
6e440ee5 26#include <TGeoManager.h>
be9c5115 27
7b5ef2e6 28#include "AliMagF.h"
be9c5115 29#include "AliTracker.h"
e23a38cb 30#include "AliGeomManager.h"
c84a5e9e 31#include "AliCluster.h"
7d0f8548 32#include "AliKalmanTrack.h"
41377c29 33
6e440ee5 34extern TGeoManager *gGeoManager;
35
7d0f8548 36Bool_t AliTracker::fgUniformField=kTRUE;
7b5ef2e6 37Double_t AliTracker::fgBz=kAlmost0Field;
3b242889 38const AliMagF *AliTracker::fgkFieldMap=0;
e23a38cb 39Bool_t AliTracker::fFillResiduals=kFALSE;
40TObjArray *AliTracker::fResiduals=0;
3b242889 41
be9c5115 42ClassImp(AliTracker)
43
3b242889 44AliTracker::AliTracker():
fe12e09c 45 TObject(),
3b242889 46 fX(0),
47 fY(0),
48 fZ(0),
49 fSigmaX(0.005),
50 fSigmaY(0.005),
51 fSigmaZ(0.010)
52{
53 //--------------------------------------------------------------------
54 // The default constructor.
55 //--------------------------------------------------------------------
c9b9861a 56 if (!fgkFieldMap) AliWarning("Field map is not set. Call AliTracker::SetFieldMap before creating a tracker!");
3b242889 57}
58
fe12e09c 59//__________________________________________________________________________
60AliTracker::AliTracker(const AliTracker &atr):
61 TObject(atr),
62 fX(atr.fX),
63 fY(atr.fY),
64 fZ(atr.fZ),
65 fSigmaX(atr.fSigmaX),
66 fSigmaY(atr.fSigmaY),
67 fSigmaZ(atr.fSigmaZ)
68{
69 //--------------------------------------------------------------------
70 // The default constructor.
71 //--------------------------------------------------------------------
72 if (!fgkFieldMap) AliWarning("Field map is not set. Call AliTracker::SetFieldMap before creating a tracker!");
73}
74
75//__________________________________________________________________________
7d0f8548 76void AliTracker::SetFieldMap(const AliMagF* map, Bool_t uni) {
77 //--------------------------------------------------------------------
78 //This passes the field map to the reconstruction.
79 //--------------------------------------------------------------------
80 if (map==0) AliFatalClass("Can't access the field map !");
81
729c2fa2 82 if (fgkFieldMap) {
83 AliWarningClass("The magnetic field map has been already set !");
84 return;
85 }
86
7d0f8548 87 fgUniformField=uni;
88 fgkFieldMap=map;
89
90 //Float_t r[3]={0.,0.,0.},b[3]; map->Field(r,b);
7ebb06c3 91 //Double_t bz=-b[2];
7d0f8548 92
7ebb06c3 93 Double_t bz=-map->SolenoidField();
7b5ef2e6 94 fgBz=TMath::Sign(kAlmost0Field,bz) + bz;
7d0f8548 95
96}
97
be9c5115 98//__________________________________________________________________________
99void AliTracker::CookLabel(AliKalmanTrack *t, Float_t wrong) const {
100 //--------------------------------------------------------------------
101 //This function "cooks" a track label. If label<0, this track is fake.
102 //--------------------------------------------------------------------
103 Int_t noc=t->GetNumberOfClusters();
9b4aca55 104 if (noc<1) return;
be9c5115 105 Int_t *lb=new Int_t[noc];
106 Int_t *mx=new Int_t[noc];
107 AliCluster **clusters=new AliCluster*[noc];
108
109 Int_t i;
110 for (i=0; i<noc; i++) {
111 lb[i]=mx[i]=0;
112 Int_t index=t->GetClusterIndex(i);
113 clusters[i]=GetCluster(index);
114 }
115
116 Int_t lab=123456789;
117 for (i=0; i<noc; i++) {
118 AliCluster *c=clusters[i];
119 lab=TMath::Abs(c->GetLabel(0));
120 Int_t j;
121 for (j=0; j<noc; j++) if (lb[j]==lab || mx[j]==0) break;
122 lb[j]=lab;
123 (mx[j])++;
124 }
125
126 Int_t max=0;
127 for (i=0; i<noc; i++) if (mx[i]>max) {max=mx[i]; lab=lb[i];}
128
129 for (i=0; i<noc; i++) {
130 AliCluster *c=clusters[i];
babd135a 131 //if (TMath::Abs(c->GetLabel(1)) == lab ||
132 // TMath::Abs(c->GetLabel(2)) == lab ) max++;
133 if (TMath::Abs(c->GetLabel(0)!=lab))
134 if (TMath::Abs(c->GetLabel(1)) == lab ||
135 TMath::Abs(c->GetLabel(2)) == lab ) max++;
be9c5115 136 }
137
138 if ((1.- Float_t(max)/noc) > wrong) lab=-lab;
babd135a 139 t->SetFakeRatio((1.- Float_t(max)/noc));
be9c5115 140 t->SetLabel(lab);
141
142 delete[] lb;
143 delete[] mx;
144 delete[] clusters;
145}
146
147//____________________________________________________________________________
148void AliTracker::UseClusters(const AliKalmanTrack *t, Int_t from) const {
149 //------------------------------------------------------------------
150 //This function marks clusters associated with the track.
151 //------------------------------------------------------------------
152 Int_t noc=t->GetNumberOfClusters();
153 for (Int_t i=from; i<noc; i++) {
154 Int_t index=t->GetClusterIndex(i);
155 AliCluster *c=GetCluster(index);
156 c->Use();
157 }
158}
7b5ef2e6 159
160Double_t AliTracker::GetBz(Float_t *r) {
161 //------------------------------------------------------------------
162 // Returns Bz (kG) at the point "r" .
163 //------------------------------------------------------------------
164 Float_t b[3]; fgkFieldMap->Field(r,b);
165 Double_t bz=-Double_t(b[2]);
166 return (TMath::Sign(kAlmost0Field,bz) + bz);
167}
6e440ee5 168
169Double_t
170AliTracker::MeanMaterialBudget(Double_t *start,Double_t *end,Double_t *mparam)
171{
172 //
173 // Calculate mean material budget and material properties between
174 // the points "start" and "end".
175 //
176 // "mparam" - parameters used for the energy and multiple scattering
177 // corrections:
178 //
179 // mparam[0] - mean density: sum(x_i*rho_i)/sum(x_i) [g/cm3]
180 // mparam[1] - equivalent rad length fraction: sum(x_i/X0_i) [adimensional]
181 // mparam[2] - mean A: sum(x_i*A_i)/sum(x_i) [adimensional]
182 // mparam[3] - mean Z: sum(x_i*Z_i)/sum(x_i) [adimensional]
183 // mparam[4] - length: sum(x_i) [cm]
184 // mparam[5] - Z/A mean: sum(x_i*Z_i/A_i)/sum(x_i) [adimensional]
185 // mparam[6] - number of boundary crosses
186 //
0c4ea33b 187 // Origin: Marian Ivanov, Marian.Ivanov@cern.ch
188 //
189 // Corrections and improvements by
190 // Andrea Dainese, Andrea.Dainese@lnl.infn.it,
191 // Andrei Gheata, Andrei.Gheata@cern.ch
192 //
6e440ee5 193
194 mparam[0]=0; mparam[1]=1; mparam[2] =0; mparam[3] =0;
195 mparam[4]=0; mparam[5]=0; mparam[6]=0;
196 //
197 Double_t bparam[6]; // total parameters
198 Double_t lparam[6]; // local parameters
199
200 for (Int_t i=0;i<6;i++) bparam[i]=0;
201
202 if (!gGeoManager) {
203 printf("ERROR: no TGeo\n");
204 return 0.;
205 }
206 //
207 Double_t length;
208 Double_t dir[3];
209 length = TMath::Sqrt((end[0]-start[0])*(end[0]-start[0])+
210 (end[1]-start[1])*(end[1]-start[1])+
211 (end[2]-start[2])*(end[2]-start[2]));
212 mparam[4]=length;
213 if (length<TGeoShape::Tolerance()) return 0.0;
214 Double_t invlen = 1./length;
215 dir[0] = (end[0]-start[0])*invlen;
216 dir[1] = (end[1]-start[1])*invlen;
217 dir[2] = (end[2]-start[2])*invlen;
218
219 // Initialize start point and direction
220 TGeoNode *currentnode = 0;
221 TGeoNode *startnode = gGeoManager->InitTrack(start, dir);
222 //printf("%s length=%f\n",gGeoManager->GetPath(),length);
223 if (!startnode) {
f3b4b060 224 AliErrorClass(Form("start point out of geometry: x %f, y %f, z %f",
ff0051ed 225 start[0],start[1],start[2]));
6e440ee5 226 return 0.0;
227 }
228 TGeoMaterial *material = startnode->GetVolume()->GetMedium()->GetMaterial();
229 lparam[0] = material->GetDensity();
230 lparam[1] = material->GetRadLen();
231 lparam[2] = material->GetA();
232 lparam[3] = material->GetZ();
233 lparam[4] = length;
234 lparam[5] = lparam[3]/lparam[2];
235 if (material->IsMixture()) {
236 TGeoMixture * mixture = (TGeoMixture*)material;
237 lparam[5] =0;
238 Double_t sum =0;
239 for (Int_t iel=0;iel<mixture->GetNelements();iel++){
240 sum += mixture->GetWmixt()[iel];
241 lparam[5]+= mixture->GetZmixt()[iel]*mixture->GetWmixt()[iel]/mixture->GetAmixt()[iel];
242 }
243 lparam[5]/=sum;
244 }
245
246 // Locate next boundary within length without computing safety.
247 // Propagate either with length (if no boundary found) or just cross boundary
248 gGeoManager->FindNextBoundaryAndStep(length, kFALSE);
249 Double_t step = 0.0; // Step made
250 Double_t snext = gGeoManager->GetStep();
251 // If no boundary within proposed length, return current density
252 if (!gGeoManager->IsOnBoundary()) {
253 mparam[0] = lparam[0];
254 mparam[1] = lparam[4]/lparam[1];
255 mparam[2] = lparam[2];
256 mparam[3] = lparam[3];
257 mparam[4] = lparam[4];
258 return lparam[0];
259 }
260 // Try to cross the boundary and see what is next
261 Int_t nzero = 0;
262 while (length>TGeoShape::Tolerance()) {
263 currentnode = gGeoManager->GetCurrentNode();
264 if (snext<2.*TGeoShape::Tolerance()) nzero++;
265 else nzero = 0;
266 if (nzero>3) {
267 // This means navigation has problems on one boundary
268 // Try to cross by making a small step
269 printf("ERROR: cannot cross boundary\n");
270 mparam[0] = bparam[0]/step;
271 mparam[1] = bparam[1];
272 mparam[2] = bparam[2]/step;
273 mparam[3] = bparam[3]/step;
274 mparam[5] = bparam[5]/step;
275 mparam[4] = step;
276 mparam[0] = 0.; // if crash of navigation take mean density 0
277 mparam[1] = 1000000; // and infinite rad length
278 return bparam[0]/step;
279 }
280 mparam[6]+=1.;
281 step += snext;
282 bparam[1] += snext/lparam[1];
283 bparam[2] += snext*lparam[2];
284 bparam[3] += snext*lparam[3];
285 bparam[5] += snext*lparam[5];
286 bparam[0] += snext*lparam[0];
287
288 if (snext>=length) break;
289 if (!currentnode) break;
290 length -= snext;
291 //printf("%s snext=%f length=%f\n", currentnode->GetName(),snext,length);
292 material = currentnode->GetVolume()->GetMedium()->GetMaterial();
293 lparam[0] = material->GetDensity();
294 lparam[1] = material->GetRadLen();
295 lparam[2] = material->GetA();
296 lparam[3] = material->GetZ();
297 //printf(" %f %f %f %f\n",lparam[0],lparam[1],lparam[2],lparam[3]);
298 lparam[5] = lparam[3]/lparam[2];
299 if (material->IsMixture()) {
300 TGeoMixture * mixture = (TGeoMixture*)material;
301 lparam[5]=0;
302 Double_t sum =0;
303 for (Int_t iel=0;iel<mixture->GetNelements();iel++){
304 sum+= mixture->GetWmixt()[iel];
305 lparam[5]+= mixture->GetZmixt()[iel]*mixture->GetWmixt()[iel]/mixture->GetAmixt()[iel];
306 }
307 lparam[5]/=sum;
308 }
309 gGeoManager->FindNextBoundaryAndStep(length, kFALSE);
310 snext = gGeoManager->GetStep();
311 //printf("snext %f\n",snext);
312 }
313 mparam[0] = bparam[0]/step;
314 mparam[1] = bparam[1];
315 mparam[2] = bparam[2]/step;
316 mparam[3] = bparam[3]/step;
317 mparam[5] = bparam[5]/step;
318 return bparam[0]/step;
319}
0c4ea33b 320
321
322Bool_t
323AliTracker::PropagateTrackTo(AliExternalTrackParam *track, Double_t xToGo,
324Double_t mass, Double_t maxStep, Bool_t rotateTo, Double_t maxSnp){
325 //----------------------------------------------------------------
326 //
327 // Propagates the track to the plane X=xk (cm) using the magnetic field map
328 // and correcting for the crossed material.
329 //
330 // mass - mass used in propagation - used for energy loss correction
331 // maxStep - maximal step for propagation
332 //
333 // Origin: Marian Ivanov, Marian.Ivanov@cern.ch
334 //
335 //----------------------------------------------------------------
336 const Double_t kEpsilon = 0.00001;
337 Double_t xpos = track->GetX();
338 Double_t dir = (xpos<xToGo) ? 1.:-1.;
339 //
340 while ( (xToGo-xpos)*dir > kEpsilon){
341 Double_t step = dir*TMath::Min(TMath::Abs(xToGo-xpos), maxStep);
342 Double_t x = xpos+step;
343 Double_t xyz0[3],xyz1[3],param[7];
344 track->GetXYZ(xyz0); //starting global position
345
346 Double_t bz=GetBz(xyz0); // getting the local Bz
347
348 if (!track->GetXYZAt(x,bz,xyz1)) return kFALSE; // no prolongation
349 xyz1[2]+=kEpsilon; // waiting for bug correction in geo
350
351 if (TMath::Abs(track->GetSnpAt(x,bz)) >= maxSnp) return kFALSE;
352 if (!track->PropagateTo(x,bz)) return kFALSE;
353
354 MeanMaterialBudget(xyz0,xyz1,param);
355 Double_t xrho=param[0]*param[4], xx0=param[1];
356
357 if (!track->CorrectForMeanMaterial(xx0,xrho,mass)) return kFALSE;
358 if (rotateTo){
359 if (TMath::Abs(track->GetSnp()) >= maxSnp) return kFALSE;
360 track->GetXYZ(xyz0); // global position
361 Double_t alphan = TMath::ATan2(xyz0[1], xyz0[0]);
362 //
363 Double_t ca=TMath::Cos(alphan-track->GetAlpha()),
364 sa=TMath::Sin(alphan-track->GetAlpha());
365 Double_t sf=track->GetSnp(), cf=TMath::Sqrt(1.- sf*sf);
366 Double_t sinNew = sf*ca - cf*sa;
367 if (TMath::Abs(sinNew) >= maxSnp) return kFALSE;
368 if (!track->Rotate(alphan)) return kFALSE;
369 }
370 xpos = track->GetX();
371 }
372 return kTRUE;
373}
374
e23a38cb 375void AliTracker::FillResiduals(const AliExternalTrackParam *t,
376 Double_t *p, Double_t *cov,
377 UShort_t id, Bool_t updated) {
378 //
379 // This function fills the histograms of residuals
380 // The array of these histos is external for this AliTracker class.
381 // Normally, this array belong to AliGlobalQADataMaker class.
382 //
383 if (!fFillResiduals) return;
384 if (!fResiduals) return;
385
386 const Double_t *residuals=t->GetResiduals(p,cov,updated);
387 if (!residuals) return;
388
389 TH1F *h=0;
390 AliGeomManager::ELayerID layer=AliGeomManager::VolUIDToLayer(id);
391 h=(TH1F*)fResiduals->At(2*layer-2);
392 h->Fill(residuals[0]);
393 h=(TH1F*)fResiduals->At(2*layer-1);
394 h->Fill(residuals[1]);
395}
396