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0ee00e25 | 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 | ||
e3b2b5e5 | 16 | /////////////////////////////////////////////////////// |
17 | // // | |
18 | // // | |
19 | // Tracklet object created in the local tracking // | |
20 | // // | |
21 | // // | |
22 | /////////////////////////////////////////////////////// | |
23 | ||
0ee00e25 | 24 | #include <TGraph.h> |
25 | #include <TMath.h> | |
26 | #include <TF1.h> | |
27 | ||
6d50f529 | 28 | #include "AliLog.h" |
29 | ||
0ee00e25 | 30 | #include "AliTRDcalibDB.h" |
31 | #include "AliTRDCommonParam.h" | |
32 | #include "AliTRDpadPlane.h" | |
33 | #include "AliTRDgeometry.h" | |
0ee00e25 | 34 | #include "AliTRDmcmTracklet.h" |
35 | ||
36 | ClassImp(AliTRDmcmTracklet) | |
37 | ||
38 | //_____________________________________________________________________________ | |
39 | AliTRDmcmTracklet::AliTRDmcmTracklet() | |
6d50f529 | 40 | :TObject() |
f162af62 | 41 | ,fGeo(0) |
6d50f529 | 42 | ,fDetector(-1) |
43 | ,fRow(-1) | |
44 | ,fTrackLabel(-1) | |
45 | ,fNclusters(0) | |
46 | ,fN(0) | |
47 | ,fGPos(0) | |
48 | ,fGAmp(0) | |
49 | ,fTime0(0) | |
50 | ,fRowz(0) | |
51 | ,fSlope(0) | |
52 | ,fOffset(0) | |
53 | ,fPt(0) | |
54 | ,fdQdl(0) | |
0ee00e25 | 55 | { |
0ee00e25 | 56 | // |
57 | // AliTRDmcmTracklet default constructor | |
58 | // | |
59 | ||
0ee00e25 | 60 | for (Int_t time = 0; time < kNtimeBins; time++) { |
61 | for (Int_t icl = 0; icl < kNclsPads; icl++) { | |
62 | fADC[time][icl] = 0; | |
63 | } | |
64 | for (Int_t it = 0; it < kNdict; it++) { | |
65 | fTrack[time][it] = -1; | |
66 | } | |
67 | fTime[time] = 0; | |
68 | fCol[time] = 0; | |
69 | } | |
70 | ||
f162af62 | 71 | fGeo = new AliTRDgeometry(); |
72 | ||
0ee00e25 | 73 | } |
74 | ||
75 | //_____________________________________________________________________________ | |
76 | AliTRDmcmTracklet::AliTRDmcmTracklet(Int_t det, Int_t row, Int_t n) | |
6d50f529 | 77 | :TObject() |
f162af62 | 78 | ,fGeo(0) |
6d50f529 | 79 | ,fDetector(det) |
80 | ,fRow(row) | |
81 | ,fTrackLabel(-1) | |
82 | ,fNclusters(0) | |
83 | ,fN(n) | |
84 | ,fGPos(0) | |
85 | ,fGAmp(0) | |
86 | ,fTime0(0) | |
87 | ,fRowz(0) | |
88 | ,fSlope(0) | |
89 | ,fOffset(0) | |
90 | ,fPt(0) | |
91 | ,fdQdl(0) | |
0ee00e25 | 92 | { |
0ee00e25 | 93 | // |
94 | // AliTRDmcmTracklet default constructor | |
95 | // | |
96 | ||
0ee00e25 | 97 | for (Int_t time = 0; time < kNtimeBins; time++) { |
98 | for (Int_t icl = 0; icl < kNclsPads; icl++) { | |
99 | fADC[time][icl] = 0; | |
100 | } | |
101 | for (Int_t it = 0; it < kNdict; it++) { | |
102 | fTrack[time][it] = -1; | |
103 | } | |
104 | fTime[time] = 0; | |
105 | fCol[time] = 0; | |
106 | } | |
107 | ||
0ee00e25 | 108 | fGPos = new TGraph(0); |
109 | fGAmp = new TGraph(0); | |
110 | ||
f162af62 | 111 | fGeo = new AliTRDgeometry(); |
112 | ||
6d50f529 | 113 | } |
114 | ||
115 | //_____________________________________________________________________________ | |
116 | AliTRDmcmTracklet::AliTRDmcmTracklet(const AliTRDmcmTracklet &t) | |
117 | :TObject(t) | |
f162af62 | 118 | ,fGeo(0) |
6d50f529 | 119 | ,fDetector(t.fDetector) |
120 | ,fRow(t.fRow) | |
121 | ,fTrackLabel(t.fTrackLabel) | |
122 | ,fNclusters(t.fNclusters) | |
123 | ,fN(t.fN) | |
124 | ,fGPos(NULL) | |
125 | ,fGAmp(NULL) | |
126 | ,fTime0(t.fTime0) | |
127 | ,fRowz(t.fRowz) | |
128 | ,fSlope(t.fSlope) | |
129 | ,fOffset(t.fOffset) | |
130 | ,fPt(t.fPt) | |
131 | ,fdQdl(t.fdQdl) | |
132 | { | |
133 | // | |
134 | // AliTRDmcmTracklet copy constructor | |
135 | // | |
136 | ||
137 | for (Int_t time = 0; time < kNtimeBins; time++) { | |
138 | for (Int_t icl = 0; icl < kNclsPads; icl++) { | |
139 | ((AliTRDmcmTracklet &) t).fADC[time][icl] = 0; | |
140 | } | |
141 | for (Int_t it = 0; it < kNdict; it++) { | |
142 | ((AliTRDmcmTracklet &) t).fTrack[time][it] = -1; | |
143 | } | |
144 | ((AliTRDmcmTracklet &) t).fTime[time] = 0; | |
145 | ((AliTRDmcmTracklet &) t).fCol[time] = 0; | |
146 | } | |
0ee00e25 | 147 | |
f162af62 | 148 | if (fGeo) { |
149 | delete fGeo; | |
150 | } | |
151 | fGeo = new AliTRDgeometry(); | |
152 | ||
0ee00e25 | 153 | } |
154 | ||
155 | //_____________________________________________________________________________ | |
156 | AliTRDmcmTracklet::~AliTRDmcmTracklet() | |
157 | { | |
0ee00e25 | 158 | // |
159 | // AliTRDmcmTracklet destructor | |
160 | // | |
3fcb9908 | 161 | |
162 | if (fGPos != 0) delete fGPos; | |
163 | if (fGAmp != 0) delete fGAmp; | |
164 | ||
f162af62 | 165 | if (fGeo) { |
166 | delete fGeo; | |
167 | } | |
168 | ||
e3b2b5e5 | 169 | } |
170 | ||
171 | //_____________________________________________________________________________ | |
172 | AliTRDmcmTracklet &AliTRDmcmTracklet::operator=(const AliTRDmcmTracklet &t) | |
173 | { | |
174 | // | |
6d50f529 | 175 | // Assignment operator |
e3b2b5e5 | 176 | // |
177 | ||
178 | if (this != &t) ((AliTRDmcmTracklet &) t).Copy(*this); | |
179 | return *this; | |
180 | ||
181 | } | |
182 | ||
183 | //_____________________________________________________________________________ | |
184 | void AliTRDmcmTracklet::Copy(TObject &t) const | |
185 | { | |
186 | // | |
6d50f529 | 187 | // Copy function |
e3b2b5e5 | 188 | // |
189 | ||
190 | ((AliTRDmcmTracklet &) t).fDetector = fDetector; | |
191 | ((AliTRDmcmTracklet &) t).fRow = fRow; | |
192 | ((AliTRDmcmTracklet &) t).fTrackLabel = fTrackLabel; | |
193 | ((AliTRDmcmTracklet &) t).fNclusters = fNclusters; | |
194 | ((AliTRDmcmTracklet &) t).fN = fN; | |
195 | ((AliTRDmcmTracklet &) t).fGPos = NULL; | |
196 | ((AliTRDmcmTracklet &) t).fGAmp = NULL; | |
197 | ((AliTRDmcmTracklet &) t).fTime0 = fTime0; | |
198 | ((AliTRDmcmTracklet &) t).fRowz = fRowz; | |
199 | ((AliTRDmcmTracklet &) t).fSlope = fSlope; | |
200 | ((AliTRDmcmTracklet &) t).fOffset = fOffset; | |
201 | ((AliTRDmcmTracklet &) t).fPt = fPt; | |
202 | ((AliTRDmcmTracklet &) t).fdQdl = fdQdl; | |
203 | ||
204 | for (Int_t time = 0; time < kNtimeBins; time++) { | |
205 | for (Int_t icl = 0; icl < kNclsPads; icl++) { | |
206 | ((AliTRDmcmTracklet &) t).fADC[time][icl] = 0; | |
207 | } | |
208 | for (Int_t it = 0; it < kNdict; it++) { | |
209 | ((AliTRDmcmTracklet &) t).fTrack[time][it] = -1; | |
210 | } | |
211 | ((AliTRDmcmTracklet &) t).fTime[time] = 0; | |
212 | ((AliTRDmcmTracklet &) t).fCol[time] = 0; | |
213 | } | |
214 | ||
215 | } | |
216 | ||
217 | //_____________________________________________________________________________ | |
3fcb9908 | 218 | void AliTRDmcmTracklet::Reset() |
e3b2b5e5 | 219 | { |
220 | // | |
3fcb9908 | 221 | // Reset the tracklet information |
222 | // | |
223 | ||
224 | fDetector = -1; | |
225 | fRow = -1; | |
226 | ||
227 | for (Int_t time = 0; time < kNtimeBins; time++) { | |
228 | for (Int_t icl = 0; icl < kNclsPads; icl++) { | |
229 | fADC[time][icl] = 0; | |
230 | } | |
231 | for (Int_t it = 0; it < kNdict; it++) { | |
232 | fTrack[time][it] = -1; | |
233 | } | |
234 | fTime[time] = 0; | |
235 | fCol[time] = 0; | |
236 | } | |
237 | ||
238 | fNclusters = 0; | |
239 | fN = 0; | |
240 | fTrackLabel = -1; | |
241 | ||
242 | fGPos->Set(0); | |
243 | fGAmp->Set(0); | |
244 | ||
245 | fSlope = 0.0; | |
246 | fOffset = 0.0; | |
247 | fTime0 = 0.0; | |
248 | fRowz = 0.0; | |
249 | fPt = 0.0; | |
250 | fdQdl = 0.0; | |
251 | ||
252 | } | |
253 | ||
254 | //_____________________________________________________________________________ | |
255 | void AliTRDmcmTracklet::AddCluster(Int_t icol, Int_t itb, Float_t *adc, Int_t *track) | |
256 | { | |
e3b2b5e5 | 257 | // |
3fcb9908 | 258 | // Add a cluster to the tracklet |
e3b2b5e5 | 259 | // |
260 | ||
261 | if (fNclusters >= kNtimeBins) return; | |
262 | ||
263 | for (Int_t icl = 0; icl < kNclsPads; icl++) { | |
e3b2b5e5 | 264 | fADC[fNclusters][icl] = adc[icl]; |
265 | } | |
266 | ||
267 | fTrack[fNclusters][0] = track[0]; | |
268 | fTrack[fNclusters][1] = track[1]; | |
269 | fTrack[fNclusters][2] = track[2]; | |
270 | fTime[fNclusters] = itb; | |
271 | fCol[fNclusters] = icol; | |
272 | ||
273 | fNclusters++; | |
0ee00e25 | 274 | |
275 | } | |
276 | ||
277 | //_____________________________________________________________________________ | |
278 | void AliTRDmcmTracklet::MakeTrackletGraph(AliTRDgeometry *geo, Float_t field) | |
279 | { | |
0ee00e25 | 280 | // |
281 | // Tracklet graph of positions (global coordinates, rotated [cm]) | |
282 | // | |
283 | ||
284 | if (!geo) { | |
6d50f529 | 285 | AliError("No geometry."); |
0ee00e25 | 286 | return; |
287 | } | |
288 | ||
f162af62 | 289 | if (!AliTRDCommonParam::Instance()) { |
6d50f529 | 290 | AliError("No common parameters."); |
0ee00e25 | 291 | return; |
292 | } | |
293 | ||
294 | AliTRDcalibDB* calibration = AliTRDcalibDB::Instance(); | |
6d50f529 | 295 | if (!calibration) { |
296 | AliError("No instance of AliTRDcalibDB."); | |
0ee00e25 | 297 | return; |
298 | } | |
299 | ||
300 | Int_t iplan, icham; | |
301 | ||
302 | iplan = geo->GetPlane(fDetector); | |
303 | icham = geo->GetChamber(fDetector); | |
304 | ||
f162af62 | 305 | AliTRDpadPlane *padPlane = fGeo->GetPadPlane(iplan,icham); |
0ee00e25 | 306 | |
f162af62 | 307 | Float_t samplFreq = AliTRDCommonParam::Instance()->GetSamplingFrequency(); |
0ee00e25 | 308 | |
309 | Int_t time, col; | |
310 | Float_t amp[3]; | |
e3b2b5e5 | 311 | Float_t xpos, ypos, xzero, colSize, timeBinSize; |
312 | Float_t vDrift, omegaTau, lorentzAngle, thetaSlope; | |
313 | Float_t tiltingAngle; | |
0ee00e25 | 314 | Int_t npg = 0; |
315 | ||
316 | for (Int_t icl = 0; icl < fNclusters; icl++) { | |
317 | ||
318 | time = GetClusterTime(icl); | |
319 | ||
320 | amp[0] = GetClusterADC(icl)[0]; | |
321 | amp[1] = GetClusterADC(icl)[1]; | |
322 | amp[2] = GetClusterADC(icl)[2]; | |
323 | ||
324 | col = GetClusterCol(icl); | |
325 | ||
326 | if (amp[0] < 0.0 || amp[1] < 0.0 || amp[2] < 0.0) continue; | |
327 | ||
e3b2b5e5 | 328 | ypos = GetClusY(amp,iplan); |
0ee00e25 | 329 | |
e3b2b5e5 | 330 | colSize = padPlane->GetColSize(col); |
0ee00e25 | 331 | vDrift = calibration->GetVdrift(fDetector,col,fRow); |
e3b2b5e5 | 332 | timeBinSize = vDrift/samplFreq; |
0ee00e25 | 333 | |
334 | // From v4-03-Release to HEAD28Mar06 the sign has changed from "-" to "+" | |
335 | // due to a change in the digitizer | |
6d50f529 | 336 | omegaTau = TMath::Sign(1.0,(Double_t)field)*GetOmegaTau(vDrift,TMath::Abs(field)); |
e3b2b5e5 | 337 | lorentzAngle = TMath::ATan(omegaTau)*180.0/TMath::Pi(); |
0ee00e25 | 338 | |
e3b2b5e5 | 339 | xpos = (time+0.5) * timeBinSize; |
340 | xpos = geo->GetTime0(iplan) - xpos; | |
0ee00e25 | 341 | |
e3b2b5e5 | 342 | ypos = padPlane->GetColPos(col) - (ypos + 0.5) * colSize; |
0ee00e25 | 343 | |
344 | // ExB correction | |
e3b2b5e5 | 345 | xzero = geo->GetTime0(iplan); |
346 | ypos = ypos + (xpos-xzero) * omegaTau; | |
0ee00e25 | 347 | |
348 | // tilted pads correction | |
e3b2b5e5 | 349 | thetaSlope = - padPlane->GetRowPos(fRow)/geo->GetTime0(iplan); |
350 | tiltingAngle = padPlane->GetTiltingAngle()/180.0*TMath::Pi(); | |
351 | ypos = ypos - (xpos-xzero) * thetaSlope * TMath::Sin(tiltingAngle); | |
0ee00e25 | 352 | |
e3b2b5e5 | 353 | fGPos->SetPoint(npg,(Double_t)xpos,(Double_t)ypos); |
0ee00e25 | 354 | npg++; |
355 | ||
356 | } | |
357 | ||
358 | fGPos->Set(npg); | |
359 | ||
360 | fTime0 = geo->GetTime0(iplan) - AliTRDgeometry::CdrHght() - 0.5*AliTRDgeometry::CamHght(); | |
9e79a757 | 361 | fRowz = padPlane->GetRowPos(fRow) - padPlane->GetRowSize(fRow)/2.0; |
0ee00e25 | 362 | |
6d50f529 | 363 | Double_t xMin = 0; |
364 | Double_t xMax = 0; | |
365 | Double_t x, y; | |
366 | fGPos->GetPoint(0 ,x,y); | |
367 | xMax = x + 0.1; | |
368 | fGPos->GetPoint(npg-1,x,y); | |
369 | xMin = x - 0.1; | |
0ee00e25 | 370 | |
371 | TF1 *line = new TF1("line","[0]+x*[1]",xMin,xMax); | |
372 | fGPos->Fit(line,"WRQ0"); | |
373 | ||
374 | fOffset = line->Eval(fTime0); | |
375 | fSlope = TMath::ATan(line->GetParameter(1))*180.0/TMath::Pi(); | |
376 | ||
377 | line->Delete(); | |
378 | ||
e3b2b5e5 | 379 | Float_t fx = fTime0; |
380 | Float_t fy = fOffset; | |
0ee00e25 | 381 | |
e3b2b5e5 | 382 | Float_t infSlope = TMath::ATan(fy/fx)/TMath::Pi()*180.0; |
6d50f529 | 383 | Float_t alpha = fSlope - infSlope; |
384 | Float_t r = TMath::Sqrt(fx*fx + fy*fy)/(2.0*TMath::Sin(alpha/180.0*TMath::Pi())); | |
0ee00e25 | 385 | |
e3b2b5e5 | 386 | fPt = 0.3 * field * 0.01 * r; |
0ee00e25 | 387 | |
388 | return; | |
389 | ||
390 | } | |
391 | ||
392 | //_____________________________________________________________________________ | |
393 | void AliTRDmcmTracklet::MakeClusAmpGraph() | |
394 | { | |
395 | // | |
396 | // Tracklet graph of cluster charges | |
397 | // | |
398 | ||
6d50f529 | 399 | Int_t time; |
0ee00e25 | 400 | Float_t amp[3]; |
6d50f529 | 401 | Int_t npg = 0; |
402 | ||
0ee00e25 | 403 | fdQdl = 0.0; |
404 | for (Int_t icl = 0; icl < fNclusters; icl++) { | |
405 | ||
406 | time = GetClusterTime(icl); | |
407 | ||
408 | amp[0] = GetClusterADC(icl)[0]; | |
409 | amp[1] = GetClusterADC(icl)[1]; | |
410 | amp[2] = GetClusterADC(icl)[2]; | |
411 | ||
412 | fGAmp->SetPoint(npg,(Double_t)(time+0.5),(Double_t)(amp[0]+amp[1]+amp[2])); | |
413 | npg++; | |
414 | ||
415 | fdQdl += amp[0]+amp[1]+amp[2]; | |
416 | ||
417 | } | |
418 | ||
419 | fGAmp->Set(npg); | |
420 | ||
421 | fdQdl /= (Float_t)npg; | |
422 | ||
423 | return; | |
424 | ||
425 | } | |
426 | ||
427 | //_____________________________________________________________________________ | |
e3b2b5e5 | 428 | Float_t AliTRDmcmTracklet::GetClusY(Float_t *adc, Int_t pla) const |
0ee00e25 | 429 | { |
430 | // | |
431 | // Cluster position in the phi direction in pad units (relative to the pad border) | |
432 | // | |
433 | ||
e3b2b5e5 | 434 | Float_t ypos = 0.0; |
0ee00e25 | 435 | |
e3b2b5e5 | 436 | Float_t a0 = adc[0]; |
437 | Float_t a1 = adc[1]; | |
438 | Float_t a2 = adc[2]; | |
0ee00e25 | 439 | |
e3b2b5e5 | 440 | Float_t t1, t2, w1 ,w2; |
0ee00e25 | 441 | |
e3b2b5e5 | 442 | Float_t w = 1.0; // pad units |
0ee00e25 | 443 | |
e3b2b5e5 | 444 | Float_t sigma = 0.0; |
0ee00e25 | 445 | |
446 | switch(pla) { | |
447 | case 0: | |
e3b2b5e5 | 448 | sigma = 0.515; break; |
0ee00e25 | 449 | case 1: |
e3b2b5e5 | 450 | sigma = 0.501; break; |
0ee00e25 | 451 | case 2: |
e3b2b5e5 | 452 | sigma = 0.491; break; |
0ee00e25 | 453 | case 3: |
e3b2b5e5 | 454 | sigma = 0.481; break; |
0ee00e25 | 455 | case 4: |
e3b2b5e5 | 456 | sigma = 0.471; break; |
0ee00e25 | 457 | case 5: |
e3b2b5e5 | 458 | sigma = 0.463; break; |
0ee00e25 | 459 | default: |
6d50f529 | 460 | AliError("Wrong plane number."); |
0ee00e25 | 461 | return 0.0; |
462 | } | |
463 | ||
e3b2b5e5 | 464 | sigma *= w; |
0ee00e25 | 465 | |
e3b2b5e5 | 466 | t1 = 0.0; |
467 | w1 = 0.0; | |
468 | if( a0 > 0 ) { | |
469 | w1 = a0*a0; | |
470 | //w1 = a0; | |
471 | t1 = w1*((sigma*sigma)/w*TMath::Log(a1/a0)-0.5*w); | |
0ee00e25 | 472 | } |
e3b2b5e5 | 473 | t2 = 0.0; |
474 | w2 = 0.0; | |
475 | if( a2 > 0 ) { | |
476 | w2 = a2*a2; | |
477 | //w2 = a2; | |
478 | t2 = w2*((sigma*sigma)/w*TMath::Log(a2/a1)+0.5*w); | |
0ee00e25 | 479 | } |
480 | ||
e3b2b5e5 | 481 | ypos = w*(t1+t2)/(w1+w2); // range: -0.5*w ... +0.5*w |
0ee00e25 | 482 | |
e3b2b5e5 | 483 | return ypos; |
0ee00e25 | 484 | |
485 | } | |
486 | ||
487 | //_____________________________________________________________________________ | |
488 | void AliTRDmcmTracklet::CookLabel(Float_t frac) | |
489 | { | |
490 | // | |
491 | // Cook the track label from cluster labels | |
492 | // | |
493 | ||
494 | const Int_t kMaxTracks = 10; | |
495 | Int_t trackLabel[kMaxTracks]; | |
496 | Int_t trackCount[kMaxTracks]; | |
497 | for (Int_t it = 0; it < kMaxTracks; it++) { | |
498 | trackLabel[it] = -1; | |
499 | trackCount[it] = 0; | |
500 | } | |
501 | ||
502 | Bool_t counted; | |
503 | Int_t label, nTracks = 0; | |
504 | for (Int_t icl = 0; icl < fNclusters; icl++) { | |
505 | ||
506 | for (Int_t id = 0; id < kNdict; id++) { | |
507 | ||
508 | if (fTrack[icl][id] == -1) continue; | |
509 | ||
510 | label = fTrack[icl][id]; | |
511 | ||
512 | counted = kFALSE; | |
513 | for (Int_t it = 0; it < nTracks; it++) { | |
514 | if (label == trackLabel[it]) { | |
515 | trackCount[it]++; | |
516 | counted = kTRUE; | |
517 | break; | |
518 | } | |
519 | } | |
520 | if (!counted) { | |
521 | trackLabel[nTracks] = label; | |
522 | trackCount[nTracks]++; | |
523 | nTracks++; | |
524 | if (nTracks == kMaxTracks) { | |
6d50f529 | 525 | AliWarning("Too many tracks for this tracklet."); |
0ee00e25 | 526 | nTracks--; |
527 | break; | |
528 | } | |
529 | } | |
530 | ||
531 | } | |
532 | ||
533 | } | |
534 | ||
535 | for (Int_t it = 0; it < kMaxTracks; it++) { | |
536 | if (trackCount[it] >= (Int_t)(frac*fNclusters)) { | |
537 | fTrackLabel = trackLabel[it]; | |
538 | break; | |
539 | } | |
540 | } | |
541 | ||
542 | } | |
543 | ||
544 | //_____________________________________________________________________________ | |
e3b2b5e5 | 545 | Float_t AliTRDmcmTracklet::GetOmegaTau(Float_t vdrift, Float_t field) const |
0ee00e25 | 546 | { |
547 | // | |
548 | // Returns omega*tau (tan(Lorentz-angle)) for a given drift velocity <vd> | |
549 | // and a B-field <b> for Xe/CO2 (15%). | |
550 | // The values are according to a GARFIELD simulation. | |
551 | // | |
552 | ||
553 | // | |
554 | // Copy of the "AliTRDcalibDB" function, taking as argument the magnetic field too | |
555 | // | |
556 | ||
557 | const Int_t kNb = 5; | |
558 | Float_t p0[kNb] = { 0.004810, 0.007412, 0.010252, 0.013409, 0.016888 }; | |
559 | Float_t p1[kNb] = { 0.054875, 0.081534, 0.107333, 0.131983, 0.155455 }; | |
560 | Float_t p2[kNb] = { -0.008682, -0.012896, -0.016987, -0.020880, -0.024623 }; | |
561 | Float_t p3[kNb] = { 0.000155, 0.000238, 0.000330, 0.000428, 0.000541 }; | |
562 | ||
563 | Int_t ib = ((Int_t) (10 * (field - 0.15))); | |
564 | ib = TMath::Max( 0,ib); | |
565 | ib = TMath::Min(kNb,ib); | |
566 | ||
567 | Float_t alphaL = p0[ib] | |
6d50f529 | 568 | + p1[ib] * vdrift |
569 | + p2[ib] * vdrift*vdrift | |
570 | + p3[ib] * vdrift*vdrift*vdrift; | |
0ee00e25 | 571 | |
572 | return TMath::Tan(alphaL); | |
573 | ||
574 | } |