Small bugfix in CalculateEgdePoint
[u/mrichter/AliRoot.git] / HLT / src / AliL3Track.cxx
CommitLineData
6d4f1901 1//$Id$
2
2d04dcbf 3// Author: Anders Vestbo <mailto:vestbo$fi.uib.no>, Uli Frankenfeld <mailto:franken@fi.uib.no>
4//*-- Copyright &copy ASV
108615fc 5
118c26c3 6#include "AliL3StandardIncludes.h"
108615fc 7
8#include "AliL3RootTypes.h"
108615fc 9#include "AliL3Logging.h"
10#include "AliL3Track.h"
0391971c 11#include "AliL3Transform.h"
6d4f1901 12#include "AliL3Vertex.h"
118c26c3 13
108615fc 14
2d04dcbf 15//_____________________________________________________________
16// AliL3Track
17//
18// Track base class
02cb36b2 19//Begin_Html
20/*
21<img src="track_coordinates.gif">
22*/
23//End_Html
0391971c 24
108615fc 25ClassImp(AliL3Track)
26
27Float_t AliL3Track::BFACT = 0.0029980;
108615fc 28Double_t AliL3Track::pi=3.14159265358979323846;
29
30AliL3Track::AliL3Track()
31{
32 //Constructor
33
34 fNHits = 0;
35 fMCid = -1;
36 fKappa=0;
37 fRadius=0;
38 fCenterX=0;
39 fCenterY=0;
40 ComesFromMainVertex(false);
41 fQ = 0;
42 fPhi0=0;
43 fPsi=0;
44 fR0=0;
45 fTanl=0;
46 fZ0=0;
47 fPt=0;
48 fLength=0;
49 fIsLocal=true;
50 fRowRange[0]=0;
51 fRowRange[1]=0;
68a27388 52 memset(fHitNumbers,0,159*sizeof(UInt_t));
108615fc 53}
54
55void AliL3Track::Set(AliL3Track *tpt){
56
3a735e00 57 SetRowRange(tpt->GetFirstRow(),tpt->GetLastRow());
58 SetPhi0(tpt->GetPhi0());
59 SetKappa(tpt->GetKappa());
60 SetNHits(tpt->GetNHits());
61 SetFirstPoint(tpt->GetFirstPointX(),tpt->GetFirstPointY(),tpt->GetFirstPointZ());
62 SetLastPoint(tpt->GetLastPointX(),tpt->GetLastPointY(),tpt->GetLastPointZ());
63 SetPt(tpt->GetPt());
64 SetPsi(tpt->GetPsi());
65 SetTgl(tpt->GetTgl());
66 SetCharge(tpt->GetCharge());
67 SetHits(tpt->GetNHits(),(UInt_t *)tpt->GetHitNumbers());
4a0bee4e 68#ifdef do_mc
69 SetMCid(tpt->GetMCid());
70#endif
108615fc 71}
72
203925a9 73Int_t AliL3Track::Compare(const AliL3Track *track) const
74{
75 if(track->GetNHits() < GetNHits()) return 1;
76 if(track->GetNHits() > GetNHits()) return -1;
77 return 0;
78}
108615fc 79
80AliL3Track::~AliL3Track()
81{
203925a9 82 //Nothing to do
108615fc 83}
84
85Double_t AliL3Track::GetP() const
86{
203925a9 87 // Returns total momentum.
108615fc 88 return fabs(GetPt())*sqrt(1. + GetTgl()*GetTgl());
108615fc 89}
90
91Double_t AliL3Track::GetPseudoRapidity() const
92{
93 return 0.5 * log((GetP() + GetPz()) / (GetP() - GetPz()));
94}
eeddc64d 95
203925a9 96/*
108615fc 97Double_t AliL3Track::GetEta() const
98{
99 return GetPseudoRapidity();
100}
203925a9 101*/
eeddc64d 102
108615fc 103Double_t AliL3Track::GetRapidity() const
104{
105 Double_t m_pi = 0.13957;
106 return 0.5 * log((m_pi + GetPz()) / (m_pi - GetPz()));
107}
108
203925a9 109void AliL3Track::Rotate(Int_t slice,Bool_t tolocal)
0391971c 110{
0391971c 111 //Rotate track to global parameters
203925a9 112 //If flag tolocal is set, the track is rotated
113 //to local coordinates.
0391971c 114
0391971c 115
116 Float_t psi[1] = {GetPsi()};
203925a9 117 if(!tolocal)
494fad94 118 AliL3Transform::Local2GlobalAngle(psi,slice);
203925a9 119 else
494fad94 120 AliL3Transform::Global2LocalAngle(psi,slice);
0391971c 121 SetPsi(psi[0]);
122 Float_t first[3];
123 first[0] = GetFirstPointX();
124 first[1] = GetFirstPointY();
125 first[2] = GetFirstPointZ();
203925a9 126 if(!tolocal)
494fad94 127 AliL3Transform::Local2Global(first,slice);
203925a9 128 else
494fad94 129 AliL3Transform::Global2Local(first,slice,kTRUE);
203925a9 130
0391971c 131 SetFirstPoint(first[0],first[1],first[2]);
132 Float_t last[3];
133 last[0] = GetLastPointX();
134 last[1] = GetLastPointY();
135 last[2] = GetLastPointZ();
203925a9 136 if(!tolocal)
494fad94 137 AliL3Transform::Local2Global(last,slice);
203925a9 138 else
494fad94 139 AliL3Transform::Global2Local(last,slice,kTRUE);
0391971c 140 SetLastPoint(last[0],last[1],last[2]);
203925a9 141
6d4f1901 142 Float_t center[3] = {GetCenterX(),GetCenterY(),0};
143 if(!tolocal)
494fad94 144 AliL3Transform::Local2Global(center,slice);
6d4f1901 145 else
494fad94 146 AliL3Transform::Global2Local(center,slice,kTRUE);
6d4f1901 147 SetCenterX(center[0]);
148 SetCenterY(center[1]);
149
203925a9 150 if(!tolocal)
151 fIsLocal=kFALSE;
152 else
153 fIsLocal=kTRUE;
0391971c 154}
155
108615fc 156void AliL3Track::CalculateHelix(){
eeddc64d 157 //Calculate Radius, CenterX and CenterY from Psi, X0, Y0
108615fc 158 //
159
ef79795d 160 fRadius = fPt / (BFACT*AliL3Transform::GetBField());
3ceb3fe1 161 if(fRadius) fKappa = -fQ*1./fRadius;
108615fc 162 else fRadius = 999999; //just zero
163 Double_t trackPhi0 = fPsi + fQ *0.5 * pi;
164
165 fCenterX = fFirstPoint[0] - fRadius * cos(trackPhi0);
166 fCenterY = fFirstPoint[1] - fRadius * sin(trackPhi0);
167}
168
2d04dcbf 169Double_t AliL3Track::GetCrossingAngle(Int_t padrow)
0391971c 170{
171 //Calculate the crossing angle between track and given padrow.
2d04dcbf 172
0391971c 173 if(!IsLocal())
174 {
175 printf("Track is not given in local coordinates\n");
176 return 0;
177 }
2d04dcbf 178
0391971c 179 Float_t xyz[3];
180 if(!GetCrossingPoint(padrow,xyz))
181 printf("AliL3HoughTrack::GetCrossingPoint : Track does not cross line!!\n");
182
183 //Take the dot product of the tangent vector of the track, and
184 //vector perpendicular to the padrow.
dab230b2 185 //In order to do this, we need the tangent vector to the track at the
186 //point. This is done by rotating the radius vector by 90 degrees;
187 //rotation matrix: ( 0 1 )
188 // ( -1 0 )
0391971c 189
190 Double_t tangent[2];
0391971c 191 tangent[0] = -1.*(xyz[1] - GetCenterY())/GetRadius();
dab230b2 192 tangent[1] = (xyz[0] - GetCenterX())/GetRadius();
193
0391971c 194 Double_t perp_padrow[2] = {1,0}; //locally in slice
23f26160 195
0391971c 196 Double_t cos_beta = fabs(tangent[0]*perp_padrow[0] + tangent[1]*perp_padrow[1]);
23f26160 197 if(cos_beta > 1) cos_beta=1;
0391971c 198 return acos(cos_beta);
0391971c 199}
200
2d04dcbf 201Bool_t AliL3Track::GetCrossingPoint(Int_t padrow,Float_t *xyz)
0391971c 202{
203 //Assumes the track is given in local coordinates
204
0391971c 205 if(!IsLocal())
206 {
207 printf("GetCrossingPoint: Track is given on global coordinates\n");
208 return false;
209 }
210
494fad94 211 Double_t xHit = AliL3Transform::Row2X(padrow);
0391971c 212
213 xyz[0] = xHit;
214 Double_t aa = (xHit - GetCenterX())*(xHit - GetCenterX());
215 Double_t r2 = GetRadius()*GetRadius();
216 if(aa > r2)
217 return false;
218
219 Double_t aa2 = sqrt(r2 - aa);
220 Double_t y1 = GetCenterY() + aa2;
221 Double_t y2 = GetCenterY() - aa2;
222 xyz[1] = y1;
223 if(fabs(y2) < fabs(y1)) xyz[1] = y2;
224
225 Double_t yHit = xyz[1];
226 Double_t angle1 = atan2((yHit - GetCenterY()),(xHit - GetCenterX()));
9ca67380 227 if(angle1 < 0) angle1 += 2.*AliL3Transform::Pi();
0391971c 228 Double_t angle2 = atan2((GetFirstPointY() - GetCenterY()),(GetFirstPointX() - GetCenterX()));
9ca67380 229 if(angle2 < 0) angle2 += 2.*AliL3Transform::Pi();
0391971c 230 Double_t diff_angle = angle1 - angle2;
9ca67380 231 diff_angle = fmod(diff_angle,2*AliL3Transform::Pi());
232 if((GetCharge()*diff_angle) > 0) diff_angle = diff_angle - GetCharge()*2.*AliL3Transform::Pi();
0391971c 233 Double_t s_tot = fabs(diff_angle)*GetRadius();
234 Double_t zHit = GetFirstPointZ() + s_tot*GetTgl();
235 xyz[2] = zHit;
236
0391971c 237 return true;
238}
239
240
6d4f1901 241Bool_t AliL3Track::CalculateReferencePoint(Double_t angle,Double_t radius){
9ca67380 242 // Global coordinate: crossing point with y = ax+ b; a=tan(angle-AliL3Transform::Pi()/2);
108615fc 243 //
eeddc64d 244 const Double_t rr=radius;//132; //position of reference plane
245 const Double_t xr = cos(angle) * rr;
246 const Double_t yr = sin(angle) * rr;
6d4f1901 247
108615fc 248 Double_t a = tan(angle-pi/2);
249 Double_t b = yr - a * xr;
250
251 Double_t pp=(fCenterX+a*fCenterY-a*b)/(1+pow(a,2));
252 Double_t qq=(pow(fCenterX,2)+pow(fCenterY,2)-2*fCenterY*b+pow(b,2)-pow(fRadius,2))/(1+pow(a,2));
253
254 Double_t racine = pp*pp-qq;
255 if(racine<0) return IsPoint(kFALSE); //no Point
256
257 Double_t rootRacine = sqrt(racine);
258 Double_t x0 = pp+rootRacine;
259 Double_t x1 = pp-rootRacine;
260 Double_t y0 = a*x0 + b;
261 Double_t y1 = a*x1 + b;
262
263 Double_t diff0 = sqrt(pow(x0-xr,2)+pow(y0-yr,2));
264 Double_t diff1 = sqrt(pow(x1-xr,2)+pow(y1-yr,2));
265
266 if(diff0<diff1){
267 fPoint[0]=x0;
268 fPoint[1]=y0;
269 }
270 else{
271 fPoint[0]=x1;
272 fPoint[1]=y1;
273 }
274
275 Double_t pointPhi0 = atan2(fPoint[1]-fCenterY,fPoint[0]-fCenterX);
276 Double_t trackPhi0 = atan2(fFirstPoint[1]-fCenterY,fFirstPoint[0]-fCenterX);
277 if(fabs(trackPhi0-pointPhi0)>pi){
278 if(trackPhi0<pointPhi0) trackPhi0 += 2*pi;
279 else pointPhi0 += 2*pi;
280 }
281 Double_t stot = -fQ * (pointPhi0-trackPhi0) * fRadius ;
282 fPoint[2] = fFirstPoint[2] + stot * fTanl;
283
284 fPointPsi = pointPhi0 - fQ * 0.5 * pi;
285 if(fPointPsi<0.) fPointPsi+= 2*pi;
286 fPointPsi = fmod(fPointPsi, 2*pi);
287
288 return IsPoint(kTRUE);
289}
290
291Bool_t AliL3Track::CalculateEdgePoint(Double_t angle){
292 // Global coordinate: crossing point with y = ax; a=tan(angle);
293 //
4a0bee4e 294 Double_t rmin=AliL3Transform::Row2X(AliL3Transform::GetFirstRow(-1)); //min Radius of TPC
295 Double_t rmax=AliL3Transform::Row2X(AliL3Transform::GetLastRow(-1)); //max Radius of TPC
108615fc 296
297 Double_t a = tan(angle);
298 Double_t pp=(fCenterX+a*fCenterY)/(1+pow(a,2));
299 Double_t qq=(pow(fCenterX,2)+pow(fCenterY,2)-pow(fRadius,2))/(1+pow(a,2));
300 Double_t racine = pp*pp-qq;
301 if(racine<0) return IsPoint(kFALSE); //no Point
302 Double_t rootRacine = sqrt(racine);
303 Double_t x0 = pp+rootRacine;
304 Double_t x1 = pp-rootRacine;
305 Double_t y0 = a*x0;
306 Double_t y1 = a*x1;
307
308 Double_t r0 = sqrt(pow(x0,2)+pow(y0,2));
309 Double_t r1 = sqrt(pow(x1,2)+pow(y1,2));
310 //find the right crossing point:
311 //inside the TPC modules
312 Bool_t ok0 = kFALSE;
313 Bool_t ok1 = kFALSE;
472d9e24 314
108615fc 315 if(r0>rmin&&r0<rmax){
316 Double_t da=atan2(y0,x0);
472d9e24 317 if(da<0) da+=2*pi;
108615fc 318 if(fabs(da-angle)<0.5)
319 ok0 = kTRUE;
320 }
321 if(r1>rmin&&r1<rmax){
472d9e24 322 Double_t da=atan2(y1,x1);
323 if(da<0) da+=2*pi;
108615fc 324 if(fabs(da-angle)<0.5)
325 ok1 = kTRUE;
326 }
327 if(!(ok0||ok1)) return IsPoint(kFALSE); //no Point
328
329 if(ok0&&ok1){
330 Double_t diff0 = sqrt(pow(fFirstPoint[0]-x0,2)+pow(fFirstPoint[1]-y0,2));
331 Double_t diff1 = sqrt(pow(fFirstPoint[0]-x1,2)+pow(fFirstPoint[1]-y1,2));
332 if(diff0<diff1) ok1 = kFALSE; //use ok0
333 else ok0 = kFALSE; //use ok1
334 }
335 if(ok0){fPoint[0]=x0; fPoint[1]=y0;}
336 else {fPoint[0]=x1; fPoint[1]=y1;}
337
338 Double_t pointPhi0 = atan2(fPoint[1]-fCenterY,fPoint[0]-fCenterX);
339 Double_t trackPhi0 = atan2(fFirstPoint[1]-fCenterY,fFirstPoint[0]-fCenterX);
340 if(fabs(trackPhi0-pointPhi0)>pi){
341 if(trackPhi0<pointPhi0) trackPhi0 += 2*pi;
342 else pointPhi0 += 2*pi;
343 }
344 Double_t stot = -fQ * (pointPhi0-trackPhi0) * fRadius ;
345 fPoint[2] = fFirstPoint[2] + stot * fTanl;
346
347 fPointPsi = pointPhi0 - fQ * 0.5 * pi;
348 if(fPointPsi<0.) fPointPsi+= 2*pi;
349 fPointPsi = fmod(fPointPsi, 2*pi);
350
351 return IsPoint(kTRUE);
352}
353
354Bool_t AliL3Track::CalculatePoint(Double_t xplane){
355 // Local coordinate: crossing point with x plane
356 //
357 Double_t racine = pow(fRadius,2)-pow(xplane-fCenterX,2);
358 if(racine<0) return IsPoint(kFALSE);
359 Double_t rootRacine = sqrt(racine);
360
361 Double_t y0 = fCenterY + rootRacine;
362 Double_t y1 = fCenterY - rootRacine;
363 //Double_t diff0 = sqrt(pow(fFirstPoint[0]-xplane)+pow(fFirstPoint[1]-y0));
364 //Double_t diff1 = sqrt(pow(fFirstPoint[0]-xplane)+pow(fFirstPoint[1]-y1));
365 Double_t diff0 = fabs(y0-fFirstPoint[1]);
366 Double_t diff1 = fabs(y1-fFirstPoint[1]);
367
368 fPoint[0]=xplane;
369 if(diff0<diff1) fPoint[1]=y0;
370 else fPoint[1]=y1;
371
372 Double_t pointPhi0 = atan2(fPoint[1]-fCenterY,fPoint[0]-fCenterX);
373 Double_t trackPhi0 = atan2(fFirstPoint[1]-fCenterY,fFirstPoint[0]-fCenterX);
374 if(fabs(trackPhi0-pointPhi0)>pi){
375 if(trackPhi0<pointPhi0) trackPhi0 += 2*pi;
376 else pointPhi0 += 2*pi;
377 }
378 Double_t stot = -fQ * (pointPhi0-trackPhi0) * fRadius ;
379 fPoint[2] = fFirstPoint[2] + stot * fTanl;
380
381 fPointPsi = pointPhi0 - fQ * 0.5 * pi;
382 if(fPointPsi<0.) fPointPsi+= 2*pi;
383 fPointPsi = fmod(fPointPsi, 2*pi);
384
385 return IsPoint(kTRUE);
386}
387
6d4f1901 388void AliL3Track::GetClosestPoint(AliL3Vertex *vertex,Double_t &closest_x,Double_t &closest_y,Double_t &closest_z)
389{
390 //Calculate the point of closest approach to the vertex
391
392
393 Double_t xc = GetCenterX() - vertex->GetX();//Shift the center of curvature with respect to the vertex
394 Double_t yc = GetCenterY() - vertex->GetY();
395
396 Double_t dist_x1 = xc*(1 + GetRadius()/sqrt(xc*xc + yc*yc));
397 Double_t dist_y1 = yc*(1 + GetRadius()/sqrt(xc*xc + yc*yc));
398 Double_t distance1 = sqrt(dist_x1*dist_x1 + dist_y1*dist_y1);
399
400 Double_t dist_x2 = xc*(1 - GetRadius()/sqrt(xc*xc + yc*yc));
401 Double_t dist_y2 = yc*(1 - GetRadius()/sqrt(xc*xc + yc*yc));
402 Double_t distance2 = sqrt(dist_x2*dist_x2 + dist_y2*dist_y2);
403
404 //Choose the closest:
405 if(distance1 < distance2)
406 {
407 closest_x = dist_x1 + vertex->GetX();
408 closest_y = dist_y1 + vertex->GetY();
409 }
410 else
411 {
412 closest_x = dist_x2 + vertex->GetX();
413 closest_y = dist_y2 + vertex->GetY();
414 }
415
416 //Get the z coordinate:
417 Double_t angle1 = atan2((closest_y-GetCenterY()),(closest_x-GetCenterX()));
9ca67380 418 if(angle1 < 0) angle1 = angle1 + 2*AliL3Transform::Pi();
6d4f1901 419
420 Double_t angle2 = atan2((GetFirstPointY()-GetCenterY()),(GetFirstPointX()-GetCenterX()));
9ca67380 421 if(angle2 < 0) angle2 = angle2 + 2*AliL3Transform::Pi();
6d4f1901 422
423 Double_t diff_angle = angle1 - angle2;
9ca67380 424 diff_angle = fmod(diff_angle,2*AliL3Transform::Pi());
6d4f1901 425
9ca67380 426 if((GetCharge()*diff_angle) < 0) diff_angle = diff_angle + GetCharge()*2*AliL3Transform::Pi();
6d4f1901 427 Double_t s_tot = fabs(diff_angle)*GetRadius();
428
429 closest_z = GetFirstPointZ() - s_tot*GetTgl();
430}