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Commit | Line | Data |
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3e87ef69 | 1 | // @(#) $Id$ |
6d4f1901 | 2 | |
2d04dcbf | 3 | // Author: Anders Vestbo <mailto:vestbo$fi.uib.no>, Uli Frankenfeld <mailto:franken@fi.uib.no> |
3e87ef69 | 4 | //*-- Copyright © ALICE HLT Group |
108615fc | 5 | |
118c26c3 | 6 | #include "AliL3StandardIncludes.h" |
14e76e91 | 7 | #include "AliL3RootTypes.h" |
108615fc | 8 | #include "AliL3RootTypes.h" |
108615fc | 9 | #include "AliL3Logging.h" |
10 | #include "AliL3Track.h" | |
0391971c | 11 | #include "AliL3Transform.h" |
6d4f1901 | 12 | #include "AliL3Vertex.h" |
de3c3890 | 13 | #include "AliL3SpacePointData.h" |
118c26c3 | 14 | |
5929c18d | 15 | #if __GNUC__ >= 3 |
3e87ef69 | 16 | using namespace std; |
17 | #endif | |
108615fc | 18 | |
3e87ef69 | 19 | /** \class AliL3Track |
20 | //<pre> | |
2d04dcbf | 21 | //_____________________________________________________________ |
22 | // AliL3Track | |
23 | // | |
24 | // Track base class | |
02cb36b2 | 25 | //Begin_Html |
3e87ef69 | 26 | //<img src="track_coordinates.gif"> |
02cb36b2 | 27 | //End_Html |
3e87ef69 | 28 | </pre> |
29 | */ | |
0391971c | 30 | |
108615fc | 31 | ClassImp(AliL3Track) |
32 | ||
108615fc | 33 | |
34 | AliL3Track::AliL3Track() | |
35 | { | |
36 | //Constructor | |
108615fc | 37 | fNHits = 0; |
38 | fMCid = -1; | |
39 | fKappa=0; | |
40 | fRadius=0; | |
41 | fCenterX=0; | |
42 | fCenterY=0; | |
43 | ComesFromMainVertex(false); | |
44 | fQ = 0; | |
45 | fPhi0=0; | |
46 | fPsi=0; | |
47 | fR0=0; | |
48 | fTanl=0; | |
49 | fZ0=0; | |
50 | fPt=0; | |
51 | fLength=0; | |
52 | fIsLocal=true; | |
53 | fRowRange[0]=0; | |
54 | fRowRange[1]=0; | |
3e87ef69 | 55 | SetFirstPoint(0,0,0); |
56 | SetLastPoint(0,0,0); | |
68a27388 | 57 | memset(fHitNumbers,0,159*sizeof(UInt_t)); |
de3c3890 | 58 | fPID = 0; |
61bd40de | 59 | |
60 | fSector=0; | |
61 | fPterr=0; | |
62 | fPsierr=0; | |
63 | fZ0err=0; | |
64 | fTanlerr=0; | |
65 | fPoint[0]=fPoint[1]=fPoint[2]=0; | |
66 | fPointPsi=0; | |
108615fc | 67 | } |
68 | ||
b1ed0288 | 69 | void AliL3Track::Set(AliL3Track *tpt) |
70 | { | |
71 | //setter | |
3a735e00 | 72 | SetRowRange(tpt->GetFirstRow(),tpt->GetLastRow()); |
73 | SetPhi0(tpt->GetPhi0()); | |
74 | SetKappa(tpt->GetKappa()); | |
75 | SetNHits(tpt->GetNHits()); | |
76 | SetFirstPoint(tpt->GetFirstPointX(),tpt->GetFirstPointY(),tpt->GetFirstPointZ()); | |
77 | SetLastPoint(tpt->GetLastPointX(),tpt->GetLastPointY(),tpt->GetLastPointZ()); | |
78 | SetPt(tpt->GetPt()); | |
79 | SetPsi(tpt->GetPsi()); | |
80 | SetTgl(tpt->GetTgl()); | |
f644512a | 81 | SetPterr(tpt->GetPterr()); |
82 | SetPsierr(tpt->GetPsierr()); | |
83 | SetTglerr(tpt->GetTglerr()); | |
3a735e00 | 84 | SetCharge(tpt->GetCharge()); |
85 | SetHits(tpt->GetNHits(),(UInt_t *)tpt->GetHitNumbers()); | |
4a0bee4e | 86 | #ifdef do_mc |
87 | SetMCid(tpt->GetMCid()); | |
88 | #endif | |
de3c3890 | 89 | SetPID(tpt->GetPID()); |
90 | SetSector(tpt->GetSector()); | |
108615fc | 91 | } |
92 | ||
203925a9 | 93 | Int_t AliL3Track::Compare(const AliL3Track *track) const |
94 | { | |
b1ed0288 | 95 | // compare tracks |
203925a9 | 96 | if(track->GetNHits() < GetNHits()) return 1; |
97 | if(track->GetNHits() > GetNHits()) return -1; | |
98 | return 0; | |
99 | } | |
108615fc | 100 | |
101 | AliL3Track::~AliL3Track() | |
102 | { | |
203925a9 | 103 | //Nothing to do |
108615fc | 104 | } |
105 | ||
106 | Double_t AliL3Track::GetP() const | |
107 | { | |
203925a9 | 108 | // Returns total momentum. |
108615fc | 109 | return fabs(GetPt())*sqrt(1. + GetTgl()*GetTgl()); |
108615fc | 110 | } |
111 | ||
112 | Double_t AliL3Track::GetPseudoRapidity() const | |
b1ed0288 | 113 | { //get pseudo rap |
108615fc | 114 | return 0.5 * log((GetP() + GetPz()) / (GetP() - GetPz())); |
115 | } | |
eeddc64d | 116 | |
203925a9 | 117 | /* |
108615fc | 118 | Double_t AliL3Track::GetEta() const |
119 | { | |
120 | return GetPseudoRapidity(); | |
121 | } | |
203925a9 | 122 | */ |
eeddc64d | 123 | |
108615fc | 124 | Double_t AliL3Track::GetRapidity() const |
b1ed0288 | 125 | { |
126 | //get rap | |
14e76e91 | 127 | const Double_t kmpi = 0.13957; |
128 | return 0.5 * log((kmpi + GetPz()) / (kmpi - GetPz())); | |
108615fc | 129 | } |
130 | ||
203925a9 | 131 | void AliL3Track::Rotate(Int_t slice,Bool_t tolocal) |
0391971c | 132 | { |
0391971c | 133 | //Rotate track to global parameters |
203925a9 | 134 | //If flag tolocal is set, the track is rotated |
135 | //to local coordinates. | |
0391971c | 136 | |
0391971c | 137 | Float_t psi[1] = {GetPsi()}; |
203925a9 | 138 | if(!tolocal) |
494fad94 | 139 | AliL3Transform::Local2GlobalAngle(psi,slice); |
203925a9 | 140 | else |
494fad94 | 141 | AliL3Transform::Global2LocalAngle(psi,slice); |
0391971c | 142 | SetPsi(psi[0]); |
143 | Float_t first[3]; | |
144 | first[0] = GetFirstPointX(); | |
145 | first[1] = GetFirstPointY(); | |
146 | first[2] = GetFirstPointZ(); | |
203925a9 | 147 | if(!tolocal) |
494fad94 | 148 | AliL3Transform::Local2Global(first,slice); |
203925a9 | 149 | else |
5a31e9df | 150 | AliL3Transform::Global2LocHLT(first,slice); |
151 | //AliL3Transform::Global2Local(first,slice,kTRUE); | |
203925a9 | 152 | |
0391971c | 153 | SetFirstPoint(first[0],first[1],first[2]); |
154 | Float_t last[3]; | |
155 | last[0] = GetLastPointX(); | |
156 | last[1] = GetLastPointY(); | |
157 | last[2] = GetLastPointZ(); | |
203925a9 | 158 | if(!tolocal) |
494fad94 | 159 | AliL3Transform::Local2Global(last,slice); |
203925a9 | 160 | else |
5a31e9df | 161 | AliL3Transform::Global2LocHLT(last,slice); |
162 | //AliL3Transform::Global2Local(last,slice,kTRUE); | |
0391971c | 163 | SetLastPoint(last[0],last[1],last[2]); |
203925a9 | 164 | |
6d4f1901 | 165 | Float_t center[3] = {GetCenterX(),GetCenterY(),0}; |
166 | if(!tolocal) | |
494fad94 | 167 | AliL3Transform::Local2Global(center,slice); |
6d4f1901 | 168 | else |
5a31e9df | 169 | AliL3Transform::Global2LocHLT(center,slice); |
170 | //AliL3Transform::Global2Local(center,slice,kTRUE); | |
6d4f1901 | 171 | SetCenterX(center[0]); |
172 | SetCenterY(center[1]); | |
173 | ||
3e87ef69 | 174 | SetPhi0(atan2(fFirstPoint[1],fFirstPoint[0])); |
175 | SetR0(sqrt(fFirstPoint[0]*fFirstPoint[0]+fFirstPoint[1]*fFirstPoint[1])); | |
176 | ||
203925a9 | 177 | if(!tolocal) |
178 | fIsLocal=kFALSE; | |
179 | else | |
180 | fIsLocal=kTRUE; | |
0391971c | 181 | } |
182 | ||
b1ed0288 | 183 | void AliL3Track::CalculateHelix() |
184 | { | |
eeddc64d | 185 | //Calculate Radius, CenterX and CenterY from Psi, X0, Y0 |
5a31e9df | 186 | fRadius = fPt / (AliL3Transform::GetBFieldValue()); |
3ceb3fe1 | 187 | if(fRadius) fKappa = -fQ*1./fRadius; |
108615fc | 188 | else fRadius = 999999; //just zero |
5a31e9df | 189 | Double_t trackPhi0 = fPsi + fQ * AliL3Transform::PiHalf(); |
108615fc | 190 | |
191 | fCenterX = fFirstPoint[0] - fRadius * cos(trackPhi0); | |
192 | fCenterY = fFirstPoint[1] - fRadius * sin(trackPhi0); | |
3e87ef69 | 193 | |
194 | SetPhi0(atan2(fFirstPoint[1],fFirstPoint[0])); | |
195 | SetR0(sqrt(fFirstPoint[0]*fFirstPoint[0]+fFirstPoint[1]*fFirstPoint[1])); | |
108615fc | 196 | } |
197 | ||
3e87ef69 | 198 | Double_t AliL3Track::GetCrossingAngle(Int_t padrow,Int_t slice) |
0391971c | 199 | { |
200 | //Calculate the crossing angle between track and given padrow. | |
0391971c | 201 | //Take the dot product of the tangent vector of the track, and |
202 | //vector perpendicular to the padrow. | |
dab230b2 | 203 | //In order to do this, we need the tangent vector to the track at the |
204 | //point. This is done by rotating the radius vector by 90 degrees; | |
205 | //rotation matrix: ( 0 1 ) | |
206 | // ( -1 0 ) | |
3e87ef69 | 207 | |
208 | Float_t angle=0;//Angle perpendicular to the padrow in local coordinates | |
209 | if(slice>=0)//Global coordinates | |
210 | { | |
211 | AliL3Transform::Local2GlobalAngle(&angle,slice); | |
212 | if(!CalculateReferencePoint(angle,AliL3Transform::Row2X(padrow))) | |
213 | cerr<<"AliL3Track::GetCrossingAngle : Track does not cross line in slice "<<slice<<" row "<<padrow<<endl; | |
214 | } | |
215 | else //should be in local coordinates | |
216 | { | |
217 | Float_t xyz[3]; | |
218 | GetCrossingPoint(padrow,xyz); | |
219 | fPoint[0] = xyz[0]; | |
220 | fPoint[1] = xyz[1]; | |
221 | fPoint[2] = xyz[2]; | |
222 | } | |
223 | ||
0391971c | 224 | Double_t tangent[2]; |
dab230b2 | 225 | |
3e87ef69 | 226 | tangent[0] = (fPoint[1] - GetCenterY())/GetRadius(); |
227 | tangent[1] = -1.*(fPoint[0] - GetCenterX())/GetRadius(); | |
228 | ||
14e76e91 | 229 | Double_t perppadrow[2] = {cos(angle),sin(angle)}; |
230 | Double_t cosbeta = fabs(tangent[0]*perppadrow[0] + tangent[1]*perppadrow[1]); | |
231 | if(cosbeta > 1) cosbeta=1; | |
232 | return acos(cosbeta); | |
0391971c | 233 | } |
234 | ||
3e87ef69 | 235 | Bool_t AliL3Track::GetCrossingPoint(Int_t padrow,Float_t *xyz) |
0391971c | 236 | { |
237 | //Assumes the track is given in local coordinates | |
3e87ef69 | 238 | |
0391971c | 239 | if(!IsLocal()) |
240 | { | |
3e87ef69 | 241 | cerr<<"GetCrossingPoint: Track is given on global coordinates"<<endl; |
0391971c | 242 | return false; |
243 | } | |
244 | ||
494fad94 | 245 | Double_t xHit = AliL3Transform::Row2X(padrow); |
0391971c | 246 | |
247 | xyz[0] = xHit; | |
248 | Double_t aa = (xHit - GetCenterX())*(xHit - GetCenterX()); | |
249 | Double_t r2 = GetRadius()*GetRadius(); | |
250 | if(aa > r2) | |
251 | return false; | |
252 | ||
253 | Double_t aa2 = sqrt(r2 - aa); | |
254 | Double_t y1 = GetCenterY() + aa2; | |
255 | Double_t y2 = GetCenterY() - aa2; | |
256 | xyz[1] = y1; | |
257 | if(fabs(y2) < fabs(y1)) xyz[1] = y2; | |
3e87ef69 | 258 | |
0391971c | 259 | Double_t yHit = xyz[1]; |
260 | Double_t angle1 = atan2((yHit - GetCenterY()),(xHit - GetCenterX())); | |
9ca67380 | 261 | if(angle1 < 0) angle1 += 2.*AliL3Transform::Pi(); |
0391971c | 262 | Double_t angle2 = atan2((GetFirstPointY() - GetCenterY()),(GetFirstPointX() - GetCenterX())); |
5a31e9df | 263 | if(angle2 < 0) angle2 += AliL3Transform::TwoPi(); |
14e76e91 | 264 | Double_t diffangle = angle1 - angle2; |
265 | diffangle = fmod(diffangle,AliL3Transform::TwoPi()); | |
266 | if((GetCharge()*diffangle) > 0) diffangle = diffangle - GetCharge()*AliL3Transform::TwoPi(); | |
267 | Double_t stot = fabs(diffangle)*GetRadius(); | |
268 | Double_t zHit = GetFirstPointZ() + stot*GetTgl(); | |
0391971c | 269 | xyz[2] = zHit; |
3e87ef69 | 270 | |
0391971c | 271 | return true; |
3e87ef69 | 272 | |
0391971c | 273 | } |
274 | ||
b1ed0288 | 275 | Bool_t AliL3Track::CalculateReferencePoint(Double_t angle,Double_t radius) |
276 | { | |
5a31e9df | 277 | // Global coordinate: crossing point with y = ax+ b; |
278 | // a=tan(angle-AliL3Transform::PiHalf()); | |
108615fc | 279 | // |
14e76e91 | 280 | const Double_t krr=radius; //position of reference plane |
281 | const Double_t kxr = cos(angle) * krr; | |
282 | const Double_t kyr = sin(angle) * krr; | |
6d4f1901 | 283 | |
5a31e9df | 284 | Double_t a = tan(angle-AliL3Transform::PiHalf()); |
14e76e91 | 285 | Double_t b = kyr - a * kxr; |
108615fc | 286 | |
287 | Double_t pp=(fCenterX+a*fCenterY-a*b)/(1+pow(a,2)); | |
288 | Double_t qq=(pow(fCenterX,2)+pow(fCenterY,2)-2*fCenterY*b+pow(b,2)-pow(fRadius,2))/(1+pow(a,2)); | |
289 | ||
290 | Double_t racine = pp*pp-qq; | |
291 | if(racine<0) return IsPoint(kFALSE); //no Point | |
292 | ||
293 | Double_t rootRacine = sqrt(racine); | |
294 | Double_t x0 = pp+rootRacine; | |
295 | Double_t x1 = pp-rootRacine; | |
296 | Double_t y0 = a*x0 + b; | |
297 | Double_t y1 = a*x1 + b; | |
298 | ||
14e76e91 | 299 | Double_t diff0 = sqrt(pow(x0-kxr,2)+pow(y0-kyr,2)); |
300 | Double_t diff1 = sqrt(pow(x1-kxr,2)+pow(y1-kyr,2)); | |
108615fc | 301 | |
302 | if(diff0<diff1){ | |
303 | fPoint[0]=x0; | |
304 | fPoint[1]=y0; | |
305 | } | |
306 | else{ | |
307 | fPoint[0]=x1; | |
308 | fPoint[1]=y1; | |
309 | } | |
310 | ||
311 | Double_t pointPhi0 = atan2(fPoint[1]-fCenterY,fPoint[0]-fCenterX); | |
312 | Double_t trackPhi0 = atan2(fFirstPoint[1]-fCenterY,fFirstPoint[0]-fCenterX); | |
5a31e9df | 313 | if(fabs(trackPhi0-pointPhi0)>AliL3Transform::Pi()){ |
314 | if(trackPhi0<pointPhi0) trackPhi0 += AliL3Transform::TwoPi(); | |
315 | else pointPhi0 += AliL3Transform::TwoPi(); | |
108615fc | 316 | } |
317 | Double_t stot = -fQ * (pointPhi0-trackPhi0) * fRadius ; | |
318 | fPoint[2] = fFirstPoint[2] + stot * fTanl; | |
319 | ||
5a31e9df | 320 | fPointPsi = pointPhi0 - fQ * AliL3Transform::PiHalf(); |
321 | if(fPointPsi<0.) fPointPsi+= AliL3Transform::TwoPi(); | |
322 | fPointPsi = fmod(fPointPsi, AliL3Transform::TwoPi()); | |
108615fc | 323 | |
324 | return IsPoint(kTRUE); | |
325 | } | |
326 | ||
b1ed0288 | 327 | Bool_t AliL3Track::CalculateEdgePoint(Double_t angle) |
328 | { | |
108615fc | 329 | // Global coordinate: crossing point with y = ax; a=tan(angle); |
330 | // | |
4a0bee4e | 331 | Double_t rmin=AliL3Transform::Row2X(AliL3Transform::GetFirstRow(-1)); //min Radius of TPC |
332 | Double_t rmax=AliL3Transform::Row2X(AliL3Transform::GetLastRow(-1)); //max Radius of TPC | |
108615fc | 333 | |
334 | Double_t a = tan(angle); | |
335 | Double_t pp=(fCenterX+a*fCenterY)/(1+pow(a,2)); | |
336 | Double_t qq=(pow(fCenterX,2)+pow(fCenterY,2)-pow(fRadius,2))/(1+pow(a,2)); | |
337 | Double_t racine = pp*pp-qq; | |
338 | if(racine<0) return IsPoint(kFALSE); //no Point | |
339 | Double_t rootRacine = sqrt(racine); | |
340 | Double_t x0 = pp+rootRacine; | |
341 | Double_t x1 = pp-rootRacine; | |
342 | Double_t y0 = a*x0; | |
343 | Double_t y1 = a*x1; | |
344 | ||
345 | Double_t r0 = sqrt(pow(x0,2)+pow(y0,2)); | |
346 | Double_t r1 = sqrt(pow(x1,2)+pow(y1,2)); | |
347 | //find the right crossing point: | |
348 | //inside the TPC modules | |
349 | Bool_t ok0 = kFALSE; | |
350 | Bool_t ok1 = kFALSE; | |
472d9e24 | 351 | |
108615fc | 352 | if(r0>rmin&&r0<rmax){ |
353 | Double_t da=atan2(y0,x0); | |
5a31e9df | 354 | if(da<0) da+=AliL3Transform::TwoPi(); |
108615fc | 355 | if(fabs(da-angle)<0.5) |
356 | ok0 = kTRUE; | |
357 | } | |
358 | if(r1>rmin&&r1<rmax){ | |
472d9e24 | 359 | Double_t da=atan2(y1,x1); |
5a31e9df | 360 | if(da<0) da+=AliL3Transform::TwoPi(); |
108615fc | 361 | if(fabs(da-angle)<0.5) |
362 | ok1 = kTRUE; | |
363 | } | |
364 | if(!(ok0||ok1)) return IsPoint(kFALSE); //no Point | |
365 | ||
366 | if(ok0&&ok1){ | |
367 | Double_t diff0 = sqrt(pow(fFirstPoint[0]-x0,2)+pow(fFirstPoint[1]-y0,2)); | |
368 | Double_t diff1 = sqrt(pow(fFirstPoint[0]-x1,2)+pow(fFirstPoint[1]-y1,2)); | |
369 | if(diff0<diff1) ok1 = kFALSE; //use ok0 | |
370 | else ok0 = kFALSE; //use ok1 | |
371 | } | |
372 | if(ok0){fPoint[0]=x0; fPoint[1]=y0;} | |
373 | else {fPoint[0]=x1; fPoint[1]=y1;} | |
374 | ||
375 | Double_t pointPhi0 = atan2(fPoint[1]-fCenterY,fPoint[0]-fCenterX); | |
376 | Double_t trackPhi0 = atan2(fFirstPoint[1]-fCenterY,fFirstPoint[0]-fCenterX); | |
5a31e9df | 377 | if(fabs(trackPhi0-pointPhi0)>AliL3Transform::Pi()){ |
378 | if(trackPhi0<pointPhi0) trackPhi0 += AliL3Transform::TwoPi(); | |
379 | else pointPhi0 += AliL3Transform::TwoPi(); | |
108615fc | 380 | } |
381 | Double_t stot = -fQ * (pointPhi0-trackPhi0) * fRadius ; | |
382 | fPoint[2] = fFirstPoint[2] + stot * fTanl; | |
383 | ||
5a31e9df | 384 | fPointPsi = pointPhi0 - fQ * AliL3Transform::PiHalf(); |
385 | if(fPointPsi<0.) fPointPsi+= AliL3Transform::TwoPi(); | |
386 | fPointPsi = fmod(fPointPsi, AliL3Transform::TwoPi()); | |
108615fc | 387 | |
388 | return IsPoint(kTRUE); | |
389 | } | |
390 | ||
b1ed0288 | 391 | Bool_t AliL3Track::CalculatePoint(Double_t xplane) |
392 | { | |
108615fc | 393 | // Local coordinate: crossing point with x plane |
394 | // | |
395 | Double_t racine = pow(fRadius,2)-pow(xplane-fCenterX,2); | |
396 | if(racine<0) return IsPoint(kFALSE); | |
397 | Double_t rootRacine = sqrt(racine); | |
398 | ||
399 | Double_t y0 = fCenterY + rootRacine; | |
400 | Double_t y1 = fCenterY - rootRacine; | |
401 | //Double_t diff0 = sqrt(pow(fFirstPoint[0]-xplane)+pow(fFirstPoint[1]-y0)); | |
402 | //Double_t diff1 = sqrt(pow(fFirstPoint[0]-xplane)+pow(fFirstPoint[1]-y1)); | |
403 | Double_t diff0 = fabs(y0-fFirstPoint[1]); | |
404 | Double_t diff1 = fabs(y1-fFirstPoint[1]); | |
405 | ||
406 | fPoint[0]=xplane; | |
407 | if(diff0<diff1) fPoint[1]=y0; | |
408 | else fPoint[1]=y1; | |
409 | ||
410 | Double_t pointPhi0 = atan2(fPoint[1]-fCenterY,fPoint[0]-fCenterX); | |
411 | Double_t trackPhi0 = atan2(fFirstPoint[1]-fCenterY,fFirstPoint[0]-fCenterX); | |
5a31e9df | 412 | if(fabs(trackPhi0-pointPhi0)>AliL3Transform::Pi()){ |
413 | if(trackPhi0<pointPhi0) trackPhi0 += AliL3Transform::TwoPi(); | |
414 | else pointPhi0 += AliL3Transform::TwoPi(); | |
108615fc | 415 | } |
416 | Double_t stot = -fQ * (pointPhi0-trackPhi0) * fRadius ; | |
417 | fPoint[2] = fFirstPoint[2] + stot * fTanl; | |
418 | ||
5a31e9df | 419 | fPointPsi = pointPhi0 - fQ * AliL3Transform::PiHalf(); |
420 | if(fPointPsi<0.) fPointPsi+= AliL3Transform::TwoPi(); | |
421 | fPointPsi = fmod(fPointPsi, AliL3Transform::TwoPi()); | |
108615fc | 422 | |
423 | return IsPoint(kTRUE); | |
424 | } | |
425 | ||
3e87ef69 | 426 | void AliL3Track::UpdateToFirstPoint() |
427 | { | |
428 | //Update track parameters to the innermost point on the track. | |
1f1942b8 | 429 | //This means that the parameters of the track will be given in the point |
430 | //of closest approach to the first innermost point, i.e. the point | |
431 | //lying on the track fit (and not the coordinates of the innermost point itself). | |
432 | //This function assumes that fFirstPoint is already set to the coordinates of the innermost | |
433 | //assigned cluster. | |
434 | // | |
435 | //During the helix-fit, the first point on the track is set to the coordinates | |
436 | //of the innermost assigned cluster. This may be ok, if you just want a fast | |
437 | //estimate of the "global" track parameters; such as the momentum etc. | |
438 | //However, if you later on want to do more precise local calculations, such | |
439 | //as impact parameter, residuals etc, you need to give the track parameters | |
440 | //according to the actual fit. | |
3e87ef69 | 441 | |
1f1942b8 | 442 | Double_t xc = GetCenterX() - GetFirstPointX(); |
443 | Double_t yc = GetCenterY() - GetFirstPointY(); | |
3e87ef69 | 444 | |
14e76e91 | 445 | Double_t distx1 = xc*(1 + GetRadius()/sqrt(xc*xc + yc*yc)); |
446 | Double_t disty1 = yc*(1 + GetRadius()/sqrt(xc*xc + yc*yc)); | |
447 | Double_t distance1 = sqrt(distx1*distx1 + disty1*disty1); | |
3e87ef69 | 448 | |
14e76e91 | 449 | Double_t distx2 = xc*(1 - GetRadius()/sqrt(xc*xc + yc*yc)); |
450 | Double_t disty2 = yc*(1 - GetRadius()/sqrt(xc*xc + yc*yc)); | |
451 | Double_t distance2 = sqrt(distx2*distx2 + disty2*disty2); | |
3e87ef69 | 452 | |
1f1942b8 | 453 | //Choose the closest: |
454 | Double_t point[2]; | |
455 | if(distance1 < distance2) | |
456 | { | |
14e76e91 | 457 | point[0] = distx1 + GetFirstPointX(); |
458 | point[1] = disty1 + GetFirstPointY(); | |
1f1942b8 | 459 | } |
460 | else | |
461 | { | |
14e76e91 | 462 | point[0] = distx2 + GetFirstPointX(); |
463 | point[1] = disty2 + GetFirstPointY(); | |
1f1942b8 | 464 | } |
465 | ||
466 | Double_t pointpsi = atan2(point[1]-GetCenterY(),point[0]-GetCenterX()); | |
5a31e9df | 467 | pointpsi -= GetCharge()*AliL3Transform::PiHalf(); |
468 | if(pointpsi < 0) pointpsi += AliL3Transform::TwoPi(); | |
3e87ef69 | 469 | |
1f1942b8 | 470 | //Update the track parameters |
471 | SetR0(sqrt(point[0]*point[0]+point[1]*point[1])); | |
472 | SetPhi0(atan2(point[1],point[0])); | |
473 | SetFirstPoint(point[0],point[1],GetZ0()); | |
474 | SetPsi(pointpsi); | |
3e87ef69 | 475 | |
3e87ef69 | 476 | } |
477 | ||
14e76e91 | 478 | void AliL3Track::GetClosestPoint(AliL3Vertex *vertex,Double_t &closestx,Double_t &closesty,Double_t &closestz) |
6d4f1901 | 479 | { |
480 | //Calculate the point of closest approach to the vertex | |
1f1942b8 | 481 | //This function calculates the minimum distance from the helix to the vertex, and choose |
482 | //the corresponding point lying on the helix as the point of closest approach. | |
6d4f1901 | 483 | |
1f1942b8 | 484 | Double_t xc = GetCenterX() - vertex->GetX(); |
6d4f1901 | 485 | Double_t yc = GetCenterY() - vertex->GetY(); |
486 | ||
14e76e91 | 487 | Double_t distx1 = xc*(1 + GetRadius()/sqrt(xc*xc + yc*yc)); |
488 | Double_t disty1 = yc*(1 + GetRadius()/sqrt(xc*xc + yc*yc)); | |
489 | Double_t distance1 = sqrt(distx1*distx1 + disty1*disty1); | |
6d4f1901 | 490 | |
14e76e91 | 491 | Double_t distx2 = xc*(1 - GetRadius()/sqrt(xc*xc + yc*yc)); |
492 | Double_t disty2 = yc*(1 - GetRadius()/sqrt(xc*xc + yc*yc)); | |
493 | Double_t distance2 = sqrt(distx2*distx2 + disty2*disty2); | |
6d4f1901 | 494 | |
495 | //Choose the closest: | |
496 | if(distance1 < distance2) | |
497 | { | |
14e76e91 | 498 | closestx = distx1 + vertex->GetX(); |
499 | closesty = disty1 + vertex->GetY(); | |
6d4f1901 | 500 | } |
501 | else | |
502 | { | |
14e76e91 | 503 | closestx = distx2 + vertex->GetX(); |
504 | closesty = disty2 + vertex->GetY(); | |
6d4f1901 | 505 | } |
506 | ||
507 | //Get the z coordinate: | |
14e76e91 | 508 | Double_t angle1 = atan2((closesty-GetCenterY()),(closestx-GetCenterX())); |
5a31e9df | 509 | if(angle1 < 0) angle1 = angle1 + AliL3Transform::TwoPi(); |
6d4f1901 | 510 | |
511 | Double_t angle2 = atan2((GetFirstPointY()-GetCenterY()),(GetFirstPointX()-GetCenterX())); | |
5a31e9df | 512 | if(angle2 < 0) angle2 = angle2 + AliL3Transform::TwoPi(); |
6d4f1901 | 513 | |
514 | Double_t diff_angle = angle1 - angle2; | |
5a31e9df | 515 | diff_angle = fmod(diff_angle,AliL3Transform::TwoPi()); |
6d4f1901 | 516 | |
5a31e9df | 517 | if((GetCharge()*diff_angle) < 0) diff_angle = diff_angle + GetCharge()*AliL3Transform::TwoPi(); |
14e76e91 | 518 | Double_t stot = fabs(diff_angle)*GetRadius(); |
519 | closestz = GetFirstPointZ() - stot*GetTgl(); | |
6d4f1901 | 520 | } |
61bd40de | 521 | |
522 | void AliL3Track::Print() const | |
e9ecfae3 | 523 | { //print out parameters of track |
61bd40de | 524 | LOG(AliL3Log::kInformational,"AliL3Track::Print","Print values") |
e9ecfae3 | 525 | <<fNHits<<" "<<fMCid<<" "<<fKappa<<" "<<fRadius<<" "<<fCenterX<<" "<<fCenterY<<" " |
526 | <<fFromMainVertex<<" "<<fRowRange[0]<<" "<<fRowRange[1]<<" "<<fSector<<" "<<fQ<<" " | |
527 | <<fTanl<<" "<<fPsi<<" "<<fPt<<" "<<fLength<<" "<<fPterr<<" "<<fPsierr<<" "<<fZ0err<<" " | |
528 | <<fTanlerr<<" "<<fPhi0<<" "<<fR0<<" "<<fZ0<<" "<<fFirstPoint[0]<<" "<<fFirstPoint[1]<<" " | |
529 | <<fFirstPoint[2]<<" "<<fLastPoint[0]<<" "<<fLastPoint[1]<<" "<<fLastPoint[2]<<" " | |
530 | <<fPoint[0]<<" "<<fPoint[1]<<" "<<fPoint[2]<<" "<<fPointPsi<<" "<<fIsPoint<<" " | |
531 | <<fIsLocal<<" "<<fPID<<ENDLOG; | |
61bd40de | 532 | } |