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c5555bc0 | 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 | ||
16 | // $Id$ | |
17 | ||
18 | /////////////////////////////////////////////////////////////////////////// | |
19 | // Class AliHelix | |
20 | // Representation and extrapolation of AliTracks in a magnetic field. | |
21 | // | |
22 | // This class is meant to provide a means to display and extrapolate | |
23 | // AliTrack objects in the presence of a constant homogeneous magnetic field. | |
24 | // | |
b847fc3d | 25 | // For track/event displays the line width, colour etc... can be set using the |
26 | // standard facilities (see TAttLine). | |
27 | // By default the linewith is set to 2 and the colour set to -1 in the constructor. | |
28 | // The latter results in an automatic colour coding according to the track charge | |
29 | // with the convention positive=red neutral=green negative=blue. | |
30 | // | |
62e01f4c | 31 | // To indicate the track starting point, the memberfunction SetMarker() |
32 | // may be used. | |
33 | // By default no marker will be displayed. | |
34 | // | |
c5555bc0 | 35 | // Examples : |
36 | // ========== | |
37 | // | |
38 | // Display and extrapolation of individual tracks | |
39 | // ---------------------------------------------- | |
40 | // Float_t vec[3]; | |
41 | // AliPosition r1; | |
42 | // Ali3Vector p; | |
43 | // AliTrack t; | |
44 | // | |
45 | // vec[0]=0; | |
46 | // vec[1]=0; | |
47 | // vec[2]=0; | |
48 | // r1.SetVector(vec,"car"); | |
49 | // | |
50 | // vec[0]=1; | |
51 | // vec[1]=0; | |
52 | // vec[2]=0.3; | |
53 | // p.SetVector(vec,"car"); | |
54 | // | |
55 | // t.Set3Momentum(p); | |
56 | // t.SetBeginPoint(r1); | |
57 | // t.SetCharge(-1); | |
58 | // t.SetMass(0.139); | |
59 | // | |
60 | // // The magnetic field vector in Tesla | |
61 | // Ali3Vector b; | |
62 | // vec[0]=0; | |
63 | // vec[1]=0; | |
64 | // vec[2]=1; | |
65 | // b.SetVector(vec,"car"); | |
66 | // | |
67 | // AliHelix* helix=new AliHelix(); | |
68 | // helix->SetB(b); | |
69 | // helix->SetTofmax(1e-7); | |
70 | // | |
71 | // TCanvas* c1=new TCanvas("c1","c1"); | |
72 | // TView* view=new TView(1); | |
73 | // view->SetRange(-1000,-1000,-1000,1000,1000,1000); | |
74 | // view->ShowAxis(); | |
75 | // | |
76 | // // Track displays | |
77 | // Double_t range[2]={0,600}; | |
78 | // helix->Display(&t,range,3); | |
79 | // t.SetCharge(-t.GetCharge()); | |
80 | // helix->Display(&t); | |
81 | // | |
82 | // // Track extrapolation | |
83 | // Double_t pars[3]={550,0.001,3}; | |
84 | // AliPosition* rext=helix->Extrapolate(&t,pars); | |
85 | // if (rext) rext->Data(); | |
86 | // ====================================================================== | |
87 | // | |
88 | // Online display of events generated via AliCollider | |
89 | // -------------------------------------------------- | |
90 | // Int_t nevents=5; // Number of events to be generated | |
91 | // Int_t jrun=1; // The run number of this batch of generated events | |
92 | // | |
93 | // cout << " ***" << endl; | |
94 | // cout << " *** AliCollider run for " << nevents << " events." << endl; | |
95 | // cout << " ***" << endl; | |
96 | // | |
97 | // AliCollider* gen=new AliCollider(); | |
98 | // | |
99 | // gen->OpenFortranFile(6,"dump.log"); | |
100 | // | |
101 | // gen->SetVertexMode(2); | |
102 | // gen->SetResolution(1e-4); | |
103 | // | |
104 | // gen->SetRunNumber(jrun); | |
105 | // gen->SetPrintFreq(1); | |
106 | // | |
107 | // gen->SetSpectatorPmin(0.01); | |
108 | // | |
109 | // Int_t zp=1; | |
110 | // Int_t ap=1; | |
111 | // Int_t zt=2; | |
112 | // Int_t at=4; | |
113 | // | |
114 | // gen->Init("fixt",zp,ap,zt,at,158); | |
115 | // | |
116 | // AliHelix* helix=new AliHelix(); | |
117 | // Float_t vec[3]={0,2,0}; | |
118 | // Ali3Vector b; | |
119 | // b.SetVector(vec,"car"); | |
120 | // helix->SetB(b); | |
121 | // | |
122 | // helix->Refresh(-1); // Refresh display after each event | |
123 | // | |
124 | // TCanvas* c1=new TCanvas("c1","c1"); | |
125 | // TView* view=new TView(1); | |
126 | // view->SetRange(-200,-200,-200,200,200,200); | |
127 | // view->ShowAxis(); | |
128 | // | |
129 | // // Prepare random number sequence for this run | |
130 | // // to obtain the number of participants for each event | |
131 | // AliRandom rndm(abs(jrun)); | |
132 | // Float_t* rans=new Float_t[nevents]; | |
133 | // rndm.Uniform(rans,nevents,2,ap+at); | |
134 | // Int_t npart=0; | |
135 | // Int_t ntk=0; | |
136 | // for (Int_t i=0; i<nevents; i++) | |
137 | // { | |
138 | // npart=rans[i]; | |
139 | // gen->MakeEvent(npart); | |
140 | // AliEvent* evt=gen->GetEvent(); | |
141 | // if (evt) | |
142 | // { | |
143 | // helix->Display(evt); | |
144 | // c1->Update(); | |
145 | // gSystem->Sleep(5000); // Some delay to keep the display on screen | |
146 | // } | |
147 | // } | |
148 | // ====================================================================== | |
149 | // | |
150 | //--- Author: Nick van Eijndhoven 17-jun-2004 Utrecht University | |
151 | //- Modified: NvE $Date$ Utrecht University | |
152 | /////////////////////////////////////////////////////////////////////////// | |
153 | ||
154 | #include "AliHelix.h" | |
155 | #include "Riostream.h" | |
156 | ||
157 | ClassImp(AliHelix) // Class implementation to enable ROOT I/O | |
158 | ||
159 | AliHelix::AliHelix() : THelix() | |
160 | { | |
161 | // Default constructor | |
162 | fRefresh=0; | |
163 | fCurves=0; | |
164 | fExt=0; | |
165 | fTofmax=1e-8; | |
62e01f4c | 166 | fMstyle=-1; |
167 | fMsize=0; | |
168 | fMcol=0; | |
169 | fEnduse=1; | |
b847fc3d | 170 | |
171 | fLineWidth=2; | |
172 | fLineColor=-1; | |
c5555bc0 | 173 | } |
174 | /////////////////////////////////////////////////////////////////////////// | |
175 | AliHelix::~AliHelix() | |
176 | { | |
177 | // Destructor to delete dynamically allocated memory. | |
178 | if (fCurves) | |
179 | { | |
180 | delete fCurves; | |
181 | fCurves=0; | |
182 | } | |
183 | if (fExt) | |
184 | { | |
185 | delete fExt; | |
186 | fExt=0; | |
187 | } | |
188 | } | |
189 | /////////////////////////////////////////////////////////////////////////// | |
190 | AliHelix::AliHelix(const AliHelix& h) : THelix(h) | |
191 | { | |
192 | // Copy constructor | |
193 | fB=h.fB; | |
194 | fRefresh=h.fRefresh; | |
aa8231b0 | 195 | fTofmax=h.fTofmax; |
196 | fMstyle=h.fMstyle; | |
197 | fMsize=h.fMsize; | |
198 | fMcol=h.fMcol; | |
199 | fEnduse=h.fEnduse; | |
c5555bc0 | 200 | } |
201 | /////////////////////////////////////////////////////////////////////////// | |
202 | void AliHelix::SetB(Ali3Vector& b) | |
203 | { | |
204 | // Set the magnetic field vector in Tesla. | |
205 | fB=b; | |
206 | ||
207 | if (fB.GetNorm()>0) | |
208 | { | |
209 | Double_t axis[3]; | |
210 | fB.GetVector(axis,"car"); | |
211 | SetAxis(axis); | |
212 | } | |
213 | } | |
214 | /////////////////////////////////////////////////////////////////////////// | |
215 | Ali3Vector& AliHelix::GetB() | |
216 | { | |
217 | // Provide the magnetic field vector in Tesla. | |
218 | return fB; | |
219 | } | |
220 | /////////////////////////////////////////////////////////////////////////// | |
221 | void AliHelix::SetTofmax(Float_t tof) | |
222 | { | |
223 | // Set the maximum time of flight for straight tracks in seconds. | |
224 | // This maximum tof will be used for drawing etc... in case no begin | |
225 | // and endpoints can be determined from the track info. | |
226 | // Notes : | |
227 | // ------- | |
228 | // 1) In case the user specifies an explicit range, it will override | |
229 | // the maximum tof limit. | |
230 | // 2) By default the tofmax is set to 10 ns in the AliHelix constructor. | |
231 | fTofmax=tof; | |
232 | } | |
233 | /////////////////////////////////////////////////////////////////////////// | |
234 | Float_t AliHelix::GetTofmax() const | |
235 | { | |
236 | // Provide the maximum time of flight for straight tracks in seconds. | |
237 | return fTofmax; | |
238 | } | |
239 | /////////////////////////////////////////////////////////////////////////// | |
62e01f4c | 240 | void AliHelix::SetMarker(Int_t style,Float_t size,Int_t col) |
241 | { | |
242 | // Specify the marker (style, size and colour) to indicate the starting point | |
243 | // of a track in a display. | |
244 | // In case col<0 the marker will have the same color as the track itself. | |
245 | // | |
246 | // Defaults are style=8, size=0.2 and col=-1. | |
247 | ||
248 | fMstyle=style; | |
249 | fMsize=size; | |
250 | fMcol=col; | |
251 | } | |
252 | /////////////////////////////////////////////////////////////////////////// | |
253 | void AliHelix::UseEndPoint(Int_t mode) | |
254 | { | |
255 | // Select usage of track endpoint in drawing and extrapolation. | |
256 | // This allows correct event displays even for very long tracks. | |
257 | // | |
258 | // mode = 0 : Do not use the track endpoint | |
259 | // 1 : Use the track endpoint | |
260 | // | |
261 | // The default value is mode=1 (which is also set in the constructor). | |
262 | ||
263 | if (mode==0 || mode==1) fEnduse=mode; | |
264 | } | |
265 | /////////////////////////////////////////////////////////////////////////// | |
c5555bc0 | 266 | void AliHelix::MakeCurve(AliTrack* t,Double_t* range,Int_t iaxis,Double_t scale) |
267 | { | |
268 | // Make the helix curve for the specified AliTrack. | |
269 | // Detailed information of all the helix points can be obtained via the | |
270 | // GetN() and GetP() memberfunctions of TPolyLine3D. | |
271 | // In case one wants to display or extrapolate an AliTrack it is preferable | |
272 | // to use the Display() or Extrapolate() memberfunctions. | |
273 | // It is assumed that the track charge is stored in elementary units | |
25eefd00 | 274 | // (i.e. charge=1 for a proton). |
c5555bc0 | 275 | // The input argument "scale" specifies the unit scale for the various |
276 | // locations where scale=0.01 indicates unit scales in cm etc... | |
277 | // In case scale<=0, the unit scale for locations is determined from the | |
278 | // begin, reference or endpoint of the track. If neither of these | |
25eefd00 | 279 | // positions is present, all locations are assumed to be given in meter. |
c5555bc0 | 280 | // The lower and upper bounds for the range are specified by range[0] and |
281 | // range[1] and the argument "iaxis" indicates along which axis this range | |
282 | // is specified. | |
283 | // The range can be specified either in the LAB frame or in the Helix frame. | |
284 | // The latter is the frame in which the Z axis points in the B direction. | |
285 | // | |
286 | // The conventions for the "iaxis" argument are the following : | |
287 | // iaxis = 1 ==> X axis in the LAB frame | |
288 | // 2 ==> Y axis in the LAB frame | |
289 | // 3 ==> Z axis in the LAB frame | |
290 | // -1 ==> X axis in the Helix frame | |
291 | // -2 ==> Y axis in the Helix frame | |
292 | // -3 ==> Z axis in the Helix frame | |
293 | // | |
294 | // In case range=0 the begin/end/reference points of the AliTrack and the | |
295 | // maximum time of flight (see the SetTofmax() memberfunction) will be used | |
296 | // and an appropriate choice for the iaxis parameter will be made automatically | |
297 | // based on the track kinematics. | |
298 | // In case the reference point is not present, the begin or endpoint will be used | |
299 | // as reference point for the 3-momentum specification. If neither of these positions | |
300 | // is present, (0,0,0) will be taken as the reference point. | |
301 | // | |
302 | // The default values are range=0, iaxis=3 and scale=-1. | |
303 | ||
304 | SetPolyLine(0); // Reset the polyline data points | |
305 | ||
306 | if (!t || (range && !iaxis)) return; | |
307 | ||
25eefd00 | 308 | Double_t energy=t->GetEnergy(1); // Track energy in GeV |
c5555bc0 | 309 | Double_t betanorm=t->GetBeta(); |
310 | ||
311 | if (energy<=0 || betanorm<=0) return; | |
312 | ||
313 | AliPosition* rbeg=t->GetBeginPoint(); | |
62e01f4c | 314 | AliPosition* rend=0; |
315 | if (fEnduse) rend=t->GetEndPoint(); | |
c5555bc0 | 316 | AliPosition* rref=t->GetReferencePoint(); |
317 | ||
318 | // Magnetic field vector or default Z-direction | |
319 | Double_t bvec[3]={0,0,1}; | |
320 | if (fB.GetNorm()>0) fB.GetVector(bvec,"car"); | |
321 | ||
322 | // The unit scale for locations if not specified by the user | |
323 | if (scale<=0) | |
324 | { | |
25eefd00 | 325 | scale=1; // Set default to meter |
c5555bc0 | 326 | if (rbeg) |
327 | { | |
328 | scale=rbeg->GetUnitScale(); | |
329 | } | |
330 | else if (rend) | |
331 | { | |
332 | scale=rend->GetUnitScale(); | |
333 | } | |
334 | else if (rref) | |
335 | { | |
336 | scale=rref->GetUnitScale(); | |
337 | } | |
338 | } | |
339 | ||
340 | Double_t c=2.99792458e8/scale; // Lightspeed in the selected unit scale | |
341 | ||
342 | // The helix angular frequency | |
343 | Double_t w=9e7*(t->GetCharge()*fB.GetNorm())/energy; | |
344 | ||
345 | // The particle velocity in the LAB frame | |
346 | Ali3Vector beta=t->GetBetaVector(); | |
347 | Ali3Vector v=beta*c; | |
348 | Double_t vel[3]; | |
349 | v.GetVector(vel,"car"); | |
350 | ||
351 | // The particle velocity in the Helix frame | |
352 | Ali3Vector betaprim=beta.GetPrimed(fRotMat); | |
353 | v=v.GetPrimed(fRotMat); | |
354 | Double_t velprim[3]; | |
355 | v.GetVector(velprim,"car"); | |
356 | ||
357 | // Check compatibility of velocity and range specification. | |
358 | if (range) | |
359 | { | |
360 | Double_t betavec[3]; | |
361 | if (iaxis>0) beta.GetVector(betavec,"car"); | |
362 | if (iaxis<0) betaprim.GetVector(betavec,"car"); | |
7a086578 | 363 | if (fabs(betavec[abs(iaxis)-1])/betanorm<1e-10) return; |
c5555bc0 | 364 | } |
365 | ||
366 | // The LAB location in which the velocity of the particle is defined | |
367 | Double_t loc[3]={0,0,0}; | |
25eefd00 | 368 | Ali3Vector rx; |
369 | Double_t scalex=-1; | |
c5555bc0 | 370 | if (rref) |
371 | { | |
25eefd00 | 372 | rx=(Ali3Vector)(*rref); |
c5555bc0 | 373 | scalex=rref->GetUnitScale(); |
374 | } | |
375 | else if (rbeg) | |
376 | { | |
25eefd00 | 377 | rx=(Ali3Vector)(*rbeg); |
c5555bc0 | 378 | scalex=rbeg->GetUnitScale(); |
379 | } | |
380 | else if (rend) | |
381 | { | |
25eefd00 | 382 | rx=(Ali3Vector)(*rend); |
c5555bc0 | 383 | scalex=rend->GetUnitScale(); |
384 | } | |
385 | ||
25eefd00 | 386 | if (scalex>0 && (scalex/scale>1.1 || scale/scalex>1.1)) rx*=scalex/scale; |
387 | rx.GetVector(loc,"car"); | |
c5555bc0 | 388 | |
389 | // Initialisation of Helix kinematics | |
390 | SetHelix(loc,vel,w,0,kUnchanged,bvec); | |
391 | ||
392 | Int_t bend=0; | |
7a086578 | 393 | if (fabs(w)>0 && fabs(fVt)>0) bend=1; |
c5555bc0 | 394 | |
395 | // Flight time boundaries. | |
396 | // The time origin t=0 is chosen to indicate the position in which | |
397 | // the particle velocity was defined. | |
398 | // The total flight time is initialised to the (user specified) tofmax. | |
399 | Double_t tmin=0,tmax=0; | |
400 | Double_t tof=fTofmax; | |
401 | Double_t dum=0; | |
402 | ||
403 | // The trajectory begin and end points | |
404 | Double_t vec1[3]={0,0,0}; | |
405 | Double_t vec2[3]={0,0,0}; | |
406 | Ali3Vector r1; | |
407 | Ali3Vector r2; | |
25eefd00 | 408 | Double_t scale1=1; |
409 | Double_t scale2=1; | |
c5555bc0 | 410 | |
411 | if (!bend) | |
412 | { | |
413 | //////////////////////////////////////// | |
414 | // Treatment of straight trajectories // | |
415 | //////////////////////////////////////// | |
416 | Ali3Vector r; | |
417 | if (range) // Specified range allows for exact flight time boundaries | |
418 | { | |
419 | if (iaxis>0) | |
420 | { | |
421 | tmin=(range[0]-loc[iaxis-1])/vel[iaxis-1]; | |
422 | tmax=(range[1]-loc[iaxis-1])/vel[iaxis-1]; | |
423 | } | |
424 | else | |
425 | { | |
426 | loc[0]=fX0; | |
427 | loc[1]=fY0; | |
428 | loc[2]=fZ0; | |
7a086578 | 429 | tmin=(range[0]-loc[abs(iaxis)-1])/velprim[abs(iaxis)-1]; |
430 | tmax=(range[1]-loc[abs(iaxis)-1])/velprim[abs(iaxis)-1]; | |
c5555bc0 | 431 | } |
432 | if (tmax<tmin) | |
433 | { | |
434 | dum=tmin; | |
435 | tmin=tmax; | |
436 | tmax=dum; | |
437 | } | |
438 | // Make the 'curve' in the LAB frame and exit. | |
439 | // Use the parametrisation : r(t)=r0+t*v | |
440 | // using the range based flight time boundaries. | |
441 | // An additional point in the middle of the trajectory is | |
442 | // generated in view of accuracy in the case of extrapolations. | |
443 | tof=tmax-tmin; | |
444 | v=beta*c; | |
25eefd00 | 445 | r1=rx; |
c5555bc0 | 446 | r=v*tmin; |
447 | r1=r1+r; | |
448 | r1.GetVector(vec1,"car"); | |
449 | SetNextPoint(float(vec1[0]),float(vec1[1]),float(vec1[2])); | |
450 | r=v*(tof/2.); | |
451 | r2=r1+r; | |
452 | r2.GetVector(vec2,"car"); | |
453 | SetNextPoint(float(vec2[0]),float(vec2[1]),float(vec2[2])); | |
454 | r=v*tof; | |
455 | r2=r1+r; | |
456 | r2.GetVector(vec2,"car"); | |
457 | SetNextPoint(float(vec2[0]),float(vec2[1]),float(vec2[2])); | |
458 | } | |
459 | else // Automatic range determination | |
460 | { | |
461 | // Initially the point with Z=0 in the Helix frame is taken as a starting point. | |
462 | // In case this point can't be reached, the point in which the particle velocity | |
463 | // was defined is taken as the starting point. | |
464 | // The endpoint is initially obtained by applying the tofmax from the start point. | |
465 | tmin=0; | |
7a086578 | 466 | if (fabs(fVz)>0) tmin=-fZ0/fVz; |
c5555bc0 | 467 | v=beta*c; |
25eefd00 | 468 | r1=rx; |
c5555bc0 | 469 | r=v*tmin; |
470 | r1=r1+r; | |
471 | ||
472 | // Override the initial begin and endpoint settings by the track data | |
473 | if (rbeg) | |
474 | { | |
475 | r1=(Ali3Vector)(*rbeg); | |
476 | scale1=rbeg->GetUnitScale(); | |
477 | // All coordinates in the selected unit scale | |
478 | if (scale1/scale>1.1 || scale/scale1>1.1) r1*=scale1/scale; | |
479 | } | |
480 | ||
481 | r=v*fTofmax; | |
482 | r2=r1+r; | |
483 | if (rend) | |
484 | { | |
485 | r2=(Ali3Vector)(*rend); | |
486 | scale2=rend->GetUnitScale(); | |
487 | // All coordinates in the selected unit scale | |
488 | if (scale2/scale>1.1 || scale/scale2>1.1) r2*=scale2/scale; | |
489 | } | |
490 | ||
491 | r1.GetVector(vec1,"car"); | |
492 | r2.GetVector(vec2,"car"); | |
493 | ||
494 | // Make the 'curve' in the LAB frame and exit. | |
495 | SetNextPoint(float(vec1[0]),float(vec1[1]),float(vec1[2])); | |
496 | SetNextPoint(float(vec2[0]),float(vec2[1]),float(vec2[2])); | |
497 | } | |
498 | } | |
499 | else | |
500 | { | |
501 | ////////////////////////////////////// | |
502 | // Treatment of curved trajectories // | |
503 | ////////////////////////////////////// | |
504 | ||
505 | // Initialisation of the flight time boundaries. | |
506 | // Based on the constant motion of the particle along the Helix Z-axis, | |
507 | // the parametrisation z(t)=z0+fVz*t in the Helix frame is used. | |
508 | // If possible the point with Z=0 in the Helix frame is taken as a starting point. | |
509 | // In case this point can't be reached, the point in which the particle velocity | |
510 | // was defined is taken as the starting point. | |
511 | tmin=0; | |
7a086578 | 512 | if (fabs(fVz)>0) tmin=-fZ0/fVz; |
c5555bc0 | 513 | tmax=tmin+fTofmax; |
514 | ||
515 | if (tmax<tmin) | |
516 | { | |
517 | dum=tmin; | |
518 | tmin=tmax; | |
519 | tmax=dum; | |
520 | } | |
521 | ||
522 | // Determination of the range in the helix frame | |
523 | ||
524 | if (!range) // Automatic range determination | |
525 | { | |
25eefd00 | 526 | scale1=1; |
527 | scale2=1; | |
c5555bc0 | 528 | if (rbeg) |
529 | { | |
530 | r1=rbeg->GetPrimed(fRotMat); | |
531 | scale1=rbeg->GetUnitScale(); | |
532 | // All coordinates in the selected unit scale | |
533 | if (scale1/scale>1.1 || scale/scale1>1.1) r1*=scale1/scale; | |
534 | // Re-calculate the tmin for this new starting point | |
535 | r1.GetVector(vec1,"car"); | |
7a086578 | 536 | if (fabs(fVz)>0) tmin=(vec1[2]-fZ0)/fVz; |
c5555bc0 | 537 | tmax=tmin+fTofmax; |
538 | } | |
539 | if (rend) | |
540 | { | |
541 | r2=rend->GetPrimed(fRotMat); | |
542 | scale2=rend->GetUnitScale(); | |
543 | // All coordinates in the selected unit scale | |
544 | if (scale2/scale>1.1 || scale/scale2>1.1) r2*=scale2/scale; | |
545 | r2.GetVector(vec2,"car"); | |
7a086578 | 546 | if (fabs(fVz)>0) tmax=(vec2[2]-fZ0)/fVz; |
c5555bc0 | 547 | } |
548 | // Make the curve on basis of the flight time boundaries and exit | |
549 | if (tmax<tmin) | |
550 | { | |
551 | dum=tmin; | |
552 | tmin=tmax; | |
553 | tmax=dum; | |
554 | } | |
555 | SetRange(tmin,tmax,kHelixT); | |
556 | } | |
557 | else // User explicitly specified range | |
558 | { | |
7a086578 | 559 | vec1[abs(iaxis)-1]=range[0]; |
560 | vec2[abs(iaxis)-1]=range[1]; | |
c5555bc0 | 561 | r1.SetVector(vec1,"car"); |
562 | r2.SetVector(vec2,"car"); | |
563 | if (iaxis>0) // Range specified in LAB frame | |
564 | { | |
565 | r1=r1.GetPrimed(fRotMat); | |
566 | r1.GetVector(vec1,"car"); | |
567 | r2=r2.GetPrimed(fRotMat); | |
568 | r2.GetVector(vec2,"car"); | |
569 | } | |
570 | // Determination of the axis component with the | |
571 | // largest range difference | |
572 | Double_t dmax=0; | |
573 | Int_t imax=0; | |
574 | Double_t test=0; | |
575 | for (Int_t i=0; i<3; i++) | |
576 | { | |
7a086578 | 577 | test=fabs(vec1[i]-vec2[i]); |
c5555bc0 | 578 | if (test>dmax) |
579 | { | |
580 | dmax=test; | |
581 | imax=i; | |
582 | } | |
583 | } | |
584 | ||
585 | Double_t rmin=vec1[imax]; | |
586 | Double_t rmax=vec2[imax]; | |
587 | if (rmax<rmin) | |
588 | { | |
589 | dum=rmin; | |
590 | rmin=rmax; | |
591 | rmax=dum; | |
592 | } | |
593 | ||
594 | // The kinematic range boundaries in the helix frame | |
595 | Double_t xmin=fX0-fVt/fW; | |
596 | Double_t xmax=fX0+fVt/fW; | |
597 | Double_t ymin=fY0-fVt/fW; | |
598 | Double_t ymax=fY0+fVt/fW; | |
599 | ||
600 | if (xmax<xmin) | |
601 | { | |
602 | dum=xmin; | |
603 | xmin=xmax; | |
604 | xmax=dum; | |
605 | } | |
606 | if (ymax<ymin) | |
607 | { | |
608 | dum=ymin; | |
609 | ymin=ymax; | |
610 | ymax=dum; | |
611 | } | |
612 | ||
613 | // Set the range for the helix | |
614 | if (imax==2 && dmax>0) SetRange(rmin,rmax,kHelixZ); | |
615 | if (imax==1) | |
616 | { | |
617 | // Limit range to kinematic boundaries if needed | |
618 | if (rmin<=ymin) rmin=ymin+1e-6*dmax; | |
619 | if (rmax>=ymax) rmax=ymax-1e-6*dmax; | |
620 | if (rmin<rmax) SetRange(rmin,rmax,kHelixY); | |
621 | } | |
622 | if (imax==0) | |
623 | { | |
624 | // Limit range to kinematic boundaries if needed | |
625 | if (rmin<=xmin) rmin=xmin+1e-6*dmax; | |
626 | if (rmax>=xmax) rmax=xmax-1e-6*dmax; | |
627 | if (rmin<rmax) SetRange(rmin,rmax,kHelixX); | |
628 | } | |
629 | } | |
630 | } | |
631 | return; | |
632 | } | |
633 | /////////////////////////////////////////////////////////////////////////// | |
634 | void AliHelix::Display(AliTrack* t,Double_t* range,Int_t iaxis,Double_t scale) | |
635 | { | |
636 | // Display the helix curve of an AliTrack. | |
637 | // Various curves can be displayed together or individually; please refer to | |
638 | // the memberfunction Refresh() for further details. | |
639 | // It is assumed that the track charge is stored in elementary units | |
25eefd00 | 640 | // (i.e. charge=1 for a proton). |
c5555bc0 | 641 | // The input argument "scale" specifies the unit scale for the various |
642 | // locations where scale=0.01 indicates unit scales in cm etc... | |
643 | // In case scale<=0, the unit scale for locations is determined from the | |
644 | // begin, reference or endpoint of the track. If neither of these | |
25eefd00 | 645 | // positions is present, all locations are assumed to be given in meter. |
c5555bc0 | 646 | // The lower and upper bounds for the range are specified by range[0] and |
647 | // range[1] and the argument "iaxis" indicates along which axis this range | |
648 | // is specified. | |
649 | // The range can be specified either in the LAB frame or in the Helix frame. | |
650 | // The latter is the frame in which the Z axis points in the B direction. | |
651 | // | |
652 | // The conventions for the "iaxis" argument are the following : | |
653 | // iaxis = 1 ==> X axis in the LAB frame | |
654 | // 2 ==> Y axis in the LAB frame | |
655 | // 3 ==> Z axis in the LAB frame | |
656 | // -1 ==> X axis in the Helix frame | |
657 | // -2 ==> Y axis in the Helix frame | |
658 | // -3 ==> Z axis in the Helix frame | |
659 | // | |
660 | // In case range=0 the begin/end/reference points of the AliTrack and the | |
661 | // maximum time of flight (see the SetTofmax() memberfunction) will be used | |
662 | // and an appropriate choice for the iaxis parameter will be made automatically | |
663 | // based on the track kinematics. | |
664 | // In case the reference point is not present, the begin or endpoint will be used | |
665 | // as reference point for the 3-momentum specification. If neither of these positions | |
666 | // is present, (0,0,0) will be taken as the reference point. | |
667 | // | |
668 | // The default values are range=0, iaxis=3 and scale=-1. | |
669 | // | |
670 | // Note : | |
671 | // ------ | |
672 | // Before any display activity, a TCanvas and a TView have to be initiated | |
673 | // first by the user like for instance | |
674 | // | |
675 | // TCanvas* c1=new TCanvas("c1","c1"); | |
676 | // TView* view=new TView(1); | |
677 | // view->SetRange(-1000,-1000,-1000,1000,1000,1000); | |
678 | // view->ShowAxis(); | |
25eefd00 | 679 | // |
680 | // The user can also use the 3D viewing facilities from the TCanvas menu | |
681 | // to open an appropriate view. | |
c5555bc0 | 682 | |
683 | if (!t || (range && !iaxis)) return; | |
684 | ||
685 | MakeCurve(t,range,iaxis,scale); | |
686 | ||
687 | if (fRefresh>0) Refresh(fRefresh); | |
688 | ||
25eefd00 | 689 | Int_t np=GetLastPoint()+1; |
c5555bc0 | 690 | if (!np) return; |
691 | ||
692 | Float_t* points=GetP(); | |
693 | TPolyLine3D* curve=new TPolyLine3D(np,points); | |
694 | ||
b847fc3d | 695 | curve->SetLineWidth(fLineWidth); |
696 | if (fLineColor<0) | |
697 | { | |
698 | Float_t q=t->GetCharge(); | |
699 | curve->SetLineColor(kGreen); | |
700 | if (q>0) curve->SetLineColor(kRed); | |
701 | if (q<0) curve->SetLineColor(kBlue); | |
702 | } | |
703 | else | |
704 | { | |
705 | curve->SetLineColor(fLineColor); | |
706 | } | |
c5555bc0 | 707 | curve->Draw(); |
708 | ||
709 | if (!fCurves) | |
710 | { | |
711 | fCurves=new TObjArray(); | |
712 | fCurves->SetOwner(); | |
713 | } | |
714 | fCurves->Add(curve); | |
62e01f4c | 715 | |
716 | // Display the marker for the track starting point | |
717 | if (fMstyle>0) | |
718 | { | |
719 | TPolyMarker3D* m=new TPolyMarker3D(); | |
720 | m->SetPoint(0,points[0],points[1],points[2]); | |
721 | m->SetMarkerStyle(fMstyle); | |
722 | m->SetMarkerSize(fMsize); | |
723 | Int_t col=curve->GetLineColor(); | |
724 | if (fMcol>0) col=fMcol; | |
725 | m->SetMarkerColor(col); | |
726 | m->Draw(); | |
727 | fCurves->Add(m); | |
728 | } | |
c5555bc0 | 729 | } |
730 | /////////////////////////////////////////////////////////////////////////// | |
731 | void AliHelix::Refresh(Int_t mode) | |
732 | { | |
733 | // Refresh the display screen before showing the next curve. | |
734 | // | |
735 | // mode = 0 : refreshing fully under user control. | |
736 | // 1 : the display screen will be refreshed automatically | |
737 | // at each individual track display. | |
738 | // -1 : the display screen will be refreshed automatically | |
739 | // at each event display. | |
740 | // | |
741 | // The default is mode=0. | |
742 | ||
7a086578 | 743 | if (abs(mode)<2) fRefresh=mode; |
c5555bc0 | 744 | if (fCurves) fCurves->Delete(); |
745 | } | |
746 | /////////////////////////////////////////////////////////////////////////// | |
747 | void AliHelix::Display(AliEvent* evt,Double_t* range,Int_t iaxis,Double_t scale) | |
748 | { | |
749 | // Display the helix curves of all tracks of the specified event. | |
750 | // Various events can be displayed together or individually; please refer to | |
751 | // the memberfunction Refresh() for further details. | |
752 | // Please refer to the track display memberfunction for further details | |
753 | // on the input arguments. | |
754 | // | |
755 | // The default values are range=0, iaxis=3 and scale=-1. | |
756 | // | |
757 | // Note : | |
758 | // ------ | |
759 | // Before any display activity, a TCanvas and a TView have to be initiated | |
760 | // first by the user like for instance | |
761 | // | |
762 | // TCanvas* c1=new TCanvas("c1","c1"); | |
763 | // TView* view=new TView(1); | |
764 | // view->SetRange(-1000,-1000,-1000,1000,1000,1000); | |
765 | // view->ShowAxis(); | |
25eefd00 | 766 | // |
767 | // The user can also use the 3D viewing facilities from the TCanvas menu | |
768 | // to open an appropriate view. | |
c5555bc0 | 769 | |
770 | if (!evt) return; | |
771 | ||
772 | if (fRefresh<0) Refresh(fRefresh); | |
773 | ||
774 | Int_t ntk=evt->GetNtracks(); | |
775 | for (Int_t jtk=1; jtk<=ntk; jtk++) | |
776 | { | |
777 | AliTrack* tx=evt->GetTrack(jtk); | |
778 | if (tx) Display(tx,range,iaxis,scale); | |
779 | } | |
780 | } | |
781 | /////////////////////////////////////////////////////////////////////////// | |
aa8231b0 | 782 | void AliHelix::Display(TObjArray* arr,Double_t* range,Int_t iaxis,Double_t scale) |
783 | { | |
784 | // Display the helix curves of all tracks in the specified array. | |
785 | // A convenient way to obtain an array with selected tracks from e.g. an AliEvent | |
786 | // is to make use of its GetTracks() selection facility. | |
787 | // Various arrays can be displayed together or individually; please refer to | |
788 | // the memberfunction Refresh() for further details. | |
789 | // Please refer to the track display memberfunction for further details | |
790 | // on the input arguments. | |
791 | // | |
792 | // The default values are range=0, iaxis=3 and scale=-1. | |
793 | // | |
794 | // Note : | |
795 | // ------ | |
796 | // Before any display activity, a TCanvas and a TView have to be initiated | |
797 | // first by the user like for instance | |
798 | // | |
799 | // TCanvas* c1=new TCanvas("c1","c1"); | |
800 | // TView* view=new TView(1); | |
801 | // view->SetRange(-1000,-1000,-1000,1000,1000,1000); | |
802 | // view->ShowAxis(); | |
25eefd00 | 803 | // |
804 | // The user can also use the 3D viewing facilities from the TCanvas menu | |
805 | // to open an appropriate view. | |
aa8231b0 | 806 | |
807 | if (!arr) return; | |
808 | ||
809 | Int_t ntk=arr->GetEntries(); | |
810 | for (Int_t jtk=0; jtk<ntk; jtk++) | |
811 | { | |
812 | TObject* obj=arr->At(jtk); | |
813 | if (!obj) continue; | |
814 | if (!(obj->InheritsFrom("AliTrack"))) continue; | |
815 | AliTrack* tx=(AliTrack*)obj; | |
816 | Display(tx,range,iaxis,scale); | |
817 | } | |
818 | } | |
819 | /////////////////////////////////////////////////////////////////////////// | |
c5555bc0 | 820 | AliPosition* AliHelix::Extrapolate(AliTrack* t,Double_t* pars,Double_t scale) |
821 | { | |
822 | // Extrapolate an AliTrack according to the corresponding helix curve | |
823 | // and provide a pointer to the impact position w.r.t. a specified plane. | |
824 | // In case the track can never reach the specified plane, the returned | |
825 | // position pointer is zero. | |
826 | // Detailed information of all the helix points used in the extrapolation | |
827 | // can be obtained via the GetN() and GetP() memberfunctions of TPolyLine3D. | |
828 | // It is assumed that the track charge is stored in elementary units | |
25eefd00 | 829 | // (i.e. charge=1 for a proton). |
c5555bc0 | 830 | // The input argument "scale" specifies the unit scale for the various |
831 | // locations where scale=0.01 indicates unit scales in cm etc... | |
832 | // In case scale<=0, the unit scale for locations is determined from the | |
833 | // begin, reference or endpoint of the track. If neither of these | |
25eefd00 | 834 | // positions is present, all locations are assumed to be given in meter. |
c5555bc0 | 835 | // The extrapolation parameters for the impact plane and required accuracy |
836 | // are specified by pars[0], pars[1] and pars[2], respectively. | |
837 | // pars[0] = coordinate value of the plane for the impact point | |
838 | // pars[1] = required accuracy on the specified impact plane coordinate | |
839 | // pars[2] = the axis along which the value of par[0] is specified | |
840 | // | |
841 | // The parameters can be specified either w.r.t. the LAB frame or the Helix frame. | |
842 | // The latter is the frame in which the Z axis points in the B direction. | |
843 | // | |
844 | // The conventions for the par[2] argument are the following : | |
845 | // par[2] = 1 ==> X axis in the LAB frame | |
846 | // 2 ==> Y axis in the LAB frame | |
847 | // 3 ==> Z axis in the LAB frame | |
848 | // -1 ==> X axis in the Helix frame | |
849 | // -2 ==> Y axis in the Helix frame | |
850 | // -3 ==> Z axis in the Helix frame | |
851 | // | |
852 | // Example : | |
853 | // --------- | |
854 | // To obtain an extrapolation to the plane Z=0 in the LAB frame | |
855 | // with an accuracy of 0.001 cm the input arguments would be | |
856 | // pars[0]=0 pars[1]=0.001 pars[2]=3 scale=0.01 | |
857 | // | |
858 | // Note : The default value for the scale is -1. | |
859 | ||
860 | if (fExt) | |
861 | { | |
862 | delete fExt; | |
863 | fExt=0; | |
864 | } | |
865 | ||
866 | if (!t || !pars) return fExt; | |
867 | ||
868 | AliPosition* rbeg=t->GetBeginPoint(); | |
869 | AliPosition* rend=t->GetEndPoint(); | |
870 | AliPosition* rref=t->GetReferencePoint(); | |
871 | ||
872 | // The unit scale for locations if not specified by the user | |
873 | if (scale<=0) | |
874 | { | |
25eefd00 | 875 | scale=1; // Set default to meter |
c5555bc0 | 876 | if (rbeg) |
877 | { | |
878 | scale=rbeg->GetUnitScale(); | |
879 | } | |
880 | else if (rend) | |
881 | { | |
882 | scale=rend->GetUnitScale(); | |
883 | } | |
884 | else if (rref) | |
885 | { | |
886 | scale=rref->GetUnitScale(); | |
887 | } | |
888 | } | |
889 | ||
890 | Double_t range[2]; | |
7a086578 | 891 | range[0]=pars[0]-fabs(pars[1])/2.; |
892 | range[1]=pars[0]+fabs(pars[1])/2.; | |
c5555bc0 | 893 | |
894 | Int_t iaxis=int(pars[2]); | |
895 | ||
896 | MakeCurve(t,range,iaxis,scale); | |
897 | ||
25eefd00 | 898 | Int_t np=GetLastPoint()+1; |
c5555bc0 | 899 | if (!np) return fExt; |
900 | ||
901 | Float_t* points=GetP(); | |
902 | ||
903 | // First point of the curve around the impact | |
904 | Int_t ip=0; | |
905 | Float_t first[3]={points[3*ip],points[3*ip+1],points[3*ip+2]}; | |
906 | ||
907 | // Last point of the curve around the impact | |
25eefd00 | 908 | ip=GetLastPoint(); |
c5555bc0 | 909 | Float_t last[3]={points[3*ip],points[3*ip+1],points[3*ip+2]}; |
910 | ||
911 | // The accuracy on the impact point | |
912 | Float_t err[3]; | |
7a086578 | 913 | err[0]=fabs(first[0]-last[0]); |
914 | err[1]=fabs(first[1]-last[1]); | |
915 | err[2]=fabs(first[2]-last[2]); | |
c5555bc0 | 916 | |
917 | // Take the middle point as impact location | |
918 | ip=np/2; | |
919 | Float_t imp[3]={points[3*ip],points[3*ip+1],points[3*ip+2]}; | |
920 | ||
921 | fExt=new AliPosition(); | |
922 | fExt->SetUnitScale(scale); | |
923 | fExt->SetPosition(imp,"car"); | |
924 | fExt->SetPositionErrors(err,"car"); | |
925 | ||
926 | return fExt; | |
927 | } | |
928 | /////////////////////////////////////////////////////////////////////////// |