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8db76038 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 * ///////////////////////////////////////////////////////////////////// *
17 * *
18 * This class performs a fast fit of helices going through the <=6 *
19 * points of the ITS, with the goal of studying tracking and *
20 * vertexing performances. *
21 * Generated kinematics is used to take into account different weights *
22 * associated to points in different layers (with different multiple *
23 * scattering-originated errors). *
24 * *
25 * Based on the work by A. Strandlie, R. Fruhwirth *
26 * *
27 * First implementation by N. Bustreo, R. Turrisi - July 2000 *
28 * *
29 * Further modifications by A. Dainese, R. Turrisi *
30 * *
31 * Contact: Rosario Turrisi, rosario.turrisi@pd.infn.it *
32 * *
33 * **************************************************************************/
34//
35//
36// Modified November, 7th 2001 by Rosario Turrisi
37// (rosario.turrisi@pd.infn.it)
38//
39// FitHelix returns different values. 0=ok, >0 =problem
40// void FitLinear -> Int_t FitLinear to give feedback of errors to FitHelix
41//
42//
43// Modified July, 30th 2001 by Rosario Turrisi
44// (rosario.turrisi@pd.infn.it)
45//
46// Fit for z now in (z,s) plane.
47// Returns parameters in order to write the helix equation
48// and find the right phase/initial point.
49//
50// "PROPER WEIGHTS": (1+R^2)^2/(\sigma_x^2 + \sigma_y^2 + \sigma_MS^2)
51//
94831058 52#include <iostream.h>
8db76038 53#include "AliITSRiemannFit.h"
54#include "AliRun.h"
55#include "TClonesArray.h"
56#include "stdio.h"
57#include "stdlib.h"
58#include "TH2.h"
59#include "TMath.h"
60#include "TF1.h"
61#include "TGraphErrors.h"
62#include "TMinuit.h"
63#include "TCanvas.h"
64#include "TStyle.h"
65#include "TRandom.h"
66#include "TParticle.h"
67#include "TFile.h"
68#include "AliITSRecPoint.h"
69#include "AliITSgeom.h"
70#include "AliITSmodule.h"
71
72ClassImp(AliITSRiemannFit)
73
74
75AliITSRiemannFit::AliITSRiemannFit() {
76 ///////////////////////////////////////////////////////////
77 // Default constructor.
78 // Set everything to zero.
79 ////////////////////////////////////////////////////////////
80
81 fSizeEvent = 0;
82 fPoints = 0;
83 fPrimaryTracks = 0;
84 fPointRecs = 0;
85 //
86 // test erase
87// fspdi = 0;
88// fspdo = 0;
89 for(Int_t i=0;i<6;i++)fPLay[i] = 0;
90
91}
92//----------------------------------------------------------------------
93
94AliITSRiemannFit::~AliITSRiemannFit() {
95 ///////////////////////////////////////////////////////////
96 // Default destructor.
97 // if arrays exist delete them. Then set everything to zero.
98 ////////////////////////////////////////////////////////////
99 if(fPointRecs!=0){
100 for(Int_t i=0;i<fSizeEvent;i++) delete[] fPointRecs[i];
101 delete[] fPointRecs;
102 } // end if fPointRecs!=0
103 fSizeEvent = 0;
104 fPointRecs = 0;
105 fPoints = 0;
106 fPrimaryTracks = 0;
107 //
108 // test erase
109// fspdi = 0;
110// fspdo = 0;
111 for(Int_t i=0;i<6;i++)fPLay[i] = 0;
112 return;
113}
114//----------------------------------------------------------------------
115
116AliITSRiemannFit::AliITSRiemannFit(Int_t size,Int_t ntracks) {
117 ///////////////////////////////////////////////////////////
118 // Constructor.
119 // Set fSizeEvent to size and fPrimaryTracks to ntracks.
120 // Others to zero.
121 ////////////////////////////////////////////////////////////
122
123 fSizeEvent = size;
124 fPoints = 0;
125 fPrimaryTracks = ntracks;
126 //
127 // test erase
128// fspdi = 0;
129// fspdo = 0;
130 Point_tl *first = new Point_tl[fSizeEvent];
131 Point_tl **PointRecs = new Point_tl*[fSizeEvent];
132 for(Int_t i=0;i<6;i++)fPLay[i] = 0;
133 for(Int_t j=0;j<fSizeEvent;j++) // create an array of struct
134 PointRecs[j] = &(first[j]);
135}
136// ---------------------------------------------------------------------
137
138void FillPoints(Point_tl **Points,Int_t &index,Float_t *xpoint,
139 Float_t *error,
140 TLorentzVector PE,TLorentzVector OT,Int_t *id,
141 Int_t track,const Char_t *name,Int_t code,
142 Float_t phiorigin){
143 ///////////////////////////////////////////////////////////////////////
144 // Fill the structure Point_tl with the proper data
145 //
146 //////////////////////////////////////////////////////////////////////
147 Float_t PI2 = 2.0*TMath::Pi();
148 Float_t phi,r,x,y,z;
149 Int_t i;
150 i = index;
151 x = xpoint[0];
152 y = xpoint[1];
153 z = xpoint[2];
154 r = sqrt(x*x+y*y);
155 phi = TMath::ATan2(y,x);
156 if(phi<0.0) phi += PI2;
157 Points[i]->phi = phi;
158 Points[i]->eta = -0.5*tan(0.5*TMath::ATan2(r,z));
159 Points[i]->fx = x;
160 Points[i]->fy = y;
161 Points[i]->fz = z;
162 Points[i]->fdx = error[0];
163 Points[i]->fdy = error[1];
164 Points[i]->fdz = error[2];
165 Points[i]->fr = r;
166 Points[i]->track = track;
167 Points[i]->lay = id[0],
168 Points[i]->lad = id[1];
169 Points[i]->det = id[2];
170 Points[i]->fMomentum = PE;
171 Points[i]->fOrigin = OT;
172 Points[i]->fPt = sqrt(PE.X()*PE.X()+PE.Y()*PE.Y());
173 Points[i]->fCode = code;
174 Points[i]->fName = name;
175 Points[i]->vertexPhi = phiorigin;
176 index++;
177 return;
178
179}
180// -----------------------------------------------------------------------
181
182void AliITSRiemannFit::InitPoints(Int_t evnt,Int_t ntracks,AliITS *ITS,
183 TTree *TR,Int_t nparticles){
184 //////////////////////////////////////////////////////////////////////
185 // Fill the class member fPointRecs with the reconstructed points
186 // Set All other members to the real values
187 //
188 /////////////////////////////////////////////////////////////////////
189 printf("\n ************* Starting Init Points *************\n");
190 TParticle *part;
191 AliITSgeom *gm = (AliITSgeom*)ITS->GetITSgeom();
192 //get pointer to modules array
193 TObjArray *ITSmodules = ITS->GetModules();
194 Int_t nmodules=ITSmodules->GetEntriesFast();
195 printf("nmodules = %d \n",nmodules);
196 // Get the points from points file
197 AliITSmodule *itsModule;
198 Int_t mod,irec;
199 Stat_t nent;
200 AliITSRecPoint *recp;
201 nent=TR->GetEntries();
202 TClonesArray *ITSrec = ITS->RecPoints();
203
204 Int_t TotRP=0;
205 for (mod=0; mod<nmodules; mod++) {
206 itsModule=(AliITSmodule*)ITSmodules->At(mod);
207 ITS->ResetRecPoints();
208 TR->GetEvent(mod);
209 Int_t nrecp = ITSrec->GetEntries();
210 if(!nrecp) continue;
211 TotRP += nrecp;
212 }
213
214 Int_t iMAX = TotRP;
215 fPrimaryTracks = ntracks;
216 fParticles = nparticles;
217 Point_tl *global = new Point_tl[iMAX];
218 fPointRecs = new Point_tl*[iMAX];
219 //
220 // test erase
221// Point_tl *first = new Point_tl[iMAX];
222// Point_tl *second = new Point_tl[iMAX];
223// fspdi = new Point_tl*[iMAX];
224// fspdo = new Point_tl*[iMAX];
225 for(Int_t j=0;j<iMAX;j++) {
226 fPointRecs[j] = &(global[j]);
227 //
228 // test erase
229// fspdi[j] = &(first[j]);
230// fspdo[j] = &(second[j]);
231 }
232
233 Int_t ieta=0,ieta2=0;
234 Int_t i,id[4],idold[4];
235 Int_t track=0;// // track of hit
236 Float_t xpoint[3],error_plus[3],error_minus[3],global_error[3]; // position and error of the point
237 TLorentzVector OT,PE;
238 Float_t locals[3],locals_error[3],locals_plus[3],locals_minus[3]; // local position and local errors
239 Float_t Phi;
240 Int_t code;
241 const char *name;
242 Int_t layer,ladder,detector;
243 Float_t xcluster,zcluster;
244 Int_t num=0,nspdi=0,nspdo=0,nsddi=0,nsddo=0,nssdi=0,nssdo=0;
245
246 for (mod=0; mod<nmodules; mod++) {
247 itsModule=(AliITSmodule*)ITSmodules->At(mod);
248 ITS->ResetRecPoints();
249 TR->GetEvent(mod);
250 Int_t nrecp = ITSrec->GetEntries();
251 if (!nrecp) continue;
252 itsModule->GetID(layer,ladder,detector);
253
254 for (irec=0;irec<nrecp;irec++) {
255 recp = (AliITSRecPoint*)ITSrec->UncheckedAt(irec);
256 track=recp->fTracks[0];
257 if(track <0 ) continue;
258 xcluster=recp->GetX(); // x on cluster
259 zcluster=recp->GetZ(); // z on cluster
260 part = (TParticle*) gAlice->Particle(track);
261 part->ProductionVertex(OT); // set the vertex
262 part->Momentum(PE); // set the vertex momentum
263 name = part->GetName();
264 code = part->GetPdgCode();
265 Phi = part->Phi();
266 id[0]=layer;
267 id[1]=ladder;
268 id[2]=detector;
269 id[3]=irec;
270 locals[0]=xcluster; // x on cluster
271 locals[1]=0.0; // y on cluster
272 locals[2]=zcluster; // z on cluster
273 locals_error[0]=sqrt(recp->GetSigmaX2());
274 locals_error[1]=0.0;
275 locals_error[2]=sqrt(recp->GetSigmaZ2());
276 locals_plus[0]=xcluster+sqrt(recp->GetSigmaX2()); // x on cluster
277 if(layer==1||layer==2) locals_plus[1]=0.0150/2; // y on cluster
278 else if(layer==3||layer==4) locals_plus[1]=0.0280/2; // y on cluster
279 else if(layer==5||layer==6) locals_plus[1]=0.0300/2; // y on cluster
280 locals_plus[2]=zcluster+sqrt(recp->GetSigmaZ2()); // z on cluster
281 locals_minus[0]=xcluster-sqrt(recp->GetSigmaX2()); // x on cluster
282 locals_minus[1]=0.0; // y on cluster
283 locals_minus[2]=zcluster-sqrt(recp->GetSigmaZ2()); // z on cluster
284
285 gm->LtoG(layer,ladder,detector,locals,xpoint);
286 gm->LtoG(layer,ladder,detector,locals_plus,error_plus);
287 gm->LtoG(layer,ladder,detector,locals_minus,error_minus);
288 global_error[0]=0.5*TMath::Abs(error_plus[0]-error_minus[0]);
289 global_error[1]=0.5*TMath::Abs(error_plus[1]-error_minus[1]);
290 global_error[2]=0.5*TMath::Abs(error_plus[2]-error_minus[2]);
291 if(track<ntracks) {
292 if(TMath::Abs(part->Eta())<=1.0) ieta++;
293 if(TMath::Abs(part->Eta())<=0.5) ieta2++;
294 }
295 if(!(id[0]==idold[0]&&id[1]==idold[1]&&
296 id[2]==idold[2]&&id[3]==idold[3])) {
297 FillPoints(fPointRecs,num,xpoint,global_error,PE,OT,id,track,name,code,Phi);
298 //
299 // test erase
300 switch (idold[0]) {
301 case 1:
302 nspdi++;
303 break;
304 case 2:
305 nspdo++;
306 break;
307 case 3:
308 nsddi++;
309 break;
310 case 4:
311 nsddo++;
312 break;
313 case 5:
314 nssdi++;
315 break;
316 case 6:
317 nssdo++;
318 break;
319 }
320// if(idold[0]==1){
321// FillPoints(fspdi,nspdi,xpoint,global_error,PE,OT,id,track,name,code,Phi);
322// }
323// if(idold[0]==2){
324
325// FillPoints(fspdo,nspdo,xpoint,global_error,PE,OT,id,track,name,code,Phi);
326// }
327// if(idold[0]==3){
328// nsddi++;
329// }
330// if(idold[0]==4){
331// nsddo++;
332// }
333// if(idold[0]==5){
334// nssdi++;
335// }
336// if(idold[0]==6){
337// nssdo++;
338// }
339 for(i=0;i<4;i++) idold[i] = id[i];
340 for(i=0;i<3;i++) xpoint[i] = 0.0;
341 } // end if id != idold
342 } // end for irec
343 }// end for mod
344
345 fPoints = num;
346 fSizeEvent = num;
347 fPLay[0] = nspdi ;
348 fPLay[1] = nspdo ;
349 fPLay[2] = nsddi ;
350 fPLay[3] = nsddo ;
351 fPLay[4] = nssdi ;
352 fPLay[5] = nssdo ;
353 printf("%d primary tracks in eta=+-1\n",ieta);
354 printf("%d primary tracks#2 in eta=+-0.5\n",ieta2);
355 printf("\nInitPoints :\n\nPoints on Layer1 : %d on Layer2 : %d\n",nspdi,nspdo);
356 printf("Points on Layer3 : %d on Layer4 : %d\n",nsddi,nsddo);
357 printf("Points on Layer5 : %d on Layer6 : %d\n",nssdi,nssdo);
358 printf("Points on all Layers: %d\n",num);
359 printf("\n ************* Init Points Finished *************\n");
360 return;
361}
362// ------------------------------------------------------------------------
363///////////////////////////////////////////////////////////
364// Functions for sorting the fPointRecs array
365///////////////////////////////////////////////////////////
366Bool_t SortZ(const Point_tl *s1,const Point_tl *s2){
367 // Z sorting function for qsort.
368 Float_t a;
369
370 a = s1->fz - s2->fz;
371 if(a<0.0) return kTRUE;
372 if(a>0.0) return kFALSE;
373 return kFALSE;
374}
375Bool_t SortTrack(const Point_tl *s1,const Point_tl *s2){
376 // track sorting function for qsort.
377 Float_t a;
378
379 a = s1->track - s2->track;
380 if(a<0.0) return kTRUE;
381 if(a>0.0) return kFALSE;
382 return kFALSE;
383}
384void hpsortTrack(Point_tl **ra,Int_t n){
385 Int_t i,ir,j,l;
386 Point_tl *rra;
387
388 if(n<2) return;
389
390 l = ((n-1) >> 1) +1; // divide 2 + 1
391 ir = n-1;
392 for(;;){
393 if(l>0){
394 rra = ra[--l]; // decrement first
395 }else{
396 rra = ra[ir];
397 ra[ir] = ra[0];
398 if(--ir == 0){ // decrement first
399 ra[0] = rra;
400 break;
401 } // if --ra == 0
402 } // end l>0
403 i = l;
404 j = l+1;
405 while(j<=ir){
406 if( j<ir && SortTrack(ra[j],ra[j+1]) ) j++;
407 if( SortTrack(rra,ra[j]) ){
408 ra[i] = ra[j];
409 i = j;
410 j <<= 1; // time 2.
411 }else{
412 break;
413 } // end if func()
414 } // end while
415 ra[i] = rra;
416 } // end for ever
417}
418void hpsortZ(Point_tl **ra,Int_t n){
419 Int_t i,ir,j,l;
420 Point_tl *rra;
421
422 if(n<2) return;
423
424 l = ((n-1) >> 1) +1; // devide 2 + 1
425 ir = n-1;
426 for(;;){
427 if(l>0){
428 rra = ra[--l]; // decrament first
429 }else{
430 rra = ra[ir];
431 ra[ir] = ra[0];
432 if(--ir == 0){ // decrament first
433 ra[0] = rra;
434 break;
435 } // if --ra == 0
436 } // end l>0
437 i = l;
438 j = l+1;
439 while(j<=ir){
440 if( j<ir && SortZ(ra[j],ra[j+1]) ) j++;
441 if( SortZ(rra,ra[j]) ){
442 ra[i] = ra[j];
443 i = j;
444 j <<= 1; // time 2.
445 }else{
446 break;
447 } // end if func()
448 } // end while
449 ra[i] = rra;
450 } // end for ever
451}
452//-----------------------------------------------------------------------
453////////////////////////////////////////////////////////////////////
454// Sorting functions
455///////////////////////////////////////////////////////////////////
456Int_t Partition(Int_t array[],Int_t left,Int_t right){
457 Int_t val = array[left];
458 Int_t lm = left - 1;
459 Int_t rm = right + 1;
460 for(;;) {
461 do
462 rm--;
463 while
464 (array[rm]>val);
465 do
466 lm++;
467 while
468 (array[lm]<val);
469 if(lm<rm){
470 Int_t tempr = array[rm];
471 array[rm]=array[lm];
472 array[lm]=tempr;
473 }
474 else
475 return rm;
476 }
477
478 return 1;
479}
480
481///////////////////////////////////////////////////////////////////////
482
483void AliITSRiemannFit::WritePoints(void) {
484 /////////////////////////////////////////////////////////////////////
485 // write the data in a file (temporary ascii)
486 /////////////////////////////////////////////////////////////////////
487 FILE *ascii= fopen("AsciiPoints.dat","w");
488 for(Int_t i=0;i<fPoints;i++) {
489 fprintf(ascii,"%d\t%d\t%f\t%f\t%f\n",fPointRecs[i]->lay,
490 fPointRecs[i]->track,fPointRecs[i]->fx,fPointRecs[i]->fy,
491 fPointRecs[i]->fz);
492 }
493 fclose(ascii);
494 return;
495}
496//-----------------------------------------------------------------------
497
498void AliITSRiemannFit::ReadPoints(void) {
499 //////////////////////////////////////////////////////////////////////
500 // read the filled array
501 /////////////////////////////////////////////////////////////////////
502 hpsortTrack(fPointRecs,fPoints);
503 for(Int_t i=0;i<fPoints;i++)
504 printf("%d\t%d\t%d\t%f\t%f\t%f\t(%.0f,%.0f,%.0f)\t%.3f\t%s\n",
505 i,fPointRecs[i]->lay,fPointRecs[i]->track,fPointRecs[i]->fx,
506 fPointRecs[i]->fy,fPointRecs[i]->fz,fPointRecs[i]->fOrigin.X(),
507 fPointRecs[i]->fOrigin.Y(),fPointRecs[i]->fOrigin.Z(),
508 fPointRecs[i]->fPt,fPointRecs[i]->fName);
509 return;
510}
511//-----------------------------------------------------------------------
512
513Int_t AliITSRiemannFit::SolveCubic(Double_t a,Double_t b,Double_t c,
514 Double_t &x1,Double_t &x2,Double_t &x3){
515 //////////////////////////////////////////////
516 /// Solve cubic equation:
517 /// x^3 + a*x^2 +b*x + c
518 ///
519 /// returns x1 , x2 , x3
520 ////////////////////////////////////////
521
522 Double_t Q = ((a*a - 3*b)/9);
523 Double_t R = ((2*a*a*a - 9*a*b +27*c)/54);
524 Double_t theta;
525 Double_t F = -2*sqrt(Q);
526 Double_t g = a/3;
527 Double_t PI2 = TMath::Pi()*2;
528
529 if( R*R>Q*Q*Q ) {
530 cout<<"\nTrack "<<"Determinant :\n\t\t No Real Solutions !!!\n"<<endl;
531 x1 = 9999999;
532 x2 = 9999999;
533 x3 = 9999999;
534 return 0;
535 }
536
537 theta = TMath::ACos( R/sqrt(Q*Q*Q));
538
539 x1 = (F*TMath::Cos(theta/3))-g;
540 x2 = (F*TMath::Cos((theta+PI2)/3))-g;
541 x3 = (F*TMath::Cos((theta-PI2)/3))-g;
542
543 return 1;
544}
545//-----------------------------------------------------------------
546
547void RiemannTransf(Int_t npoints,TVector3 **From,TVector3 **To) {
548 ///////////////////////////////////////////////////////////////////////
549 // This function apllies the transformation in the Riemann sphere
550 // for xy plane
551 ///////////////////////////////////////////////////////////////////////
552 Float_t *R = new Float_t[npoints];
553 Float_t *Theta = new Float_t[npoints];
554 Float_t PI2 = 2*TMath::Pi();
555 Float_t x=0,y=0,z=0;
556
557 for(Int_t i=0;i<npoints;i++) {
558 R[i] = sqrt(From[i]->X()*From[i]->X()+From[i]->Y()*From[i]->Y());
559 Theta[i] = TMath::ATan2(From[i]->Y(),From[i]->X());
560 if(Theta[i]<0) Theta[i]+=PI2;
561 x = R[i]*cos(Theta[i])/(1+R[i]*R[i]);
562 y = R[i]*sin(Theta[i])/(1+R[i]*R[i]);
563 z = R[i]*R[i]/(1+R[i]*R[i]);
564 To[i]->SetXYZ(x,y,z);
565 }
566 delete[] R;
567 delete[] Theta;
568 return;
569}
570
571
572//---------------------------------------------------------------------
573
574Int_t FitLinear(Int_t npoints, TVector3 **input, TVector3 **errors, Double_t omega,
575 Double_t &thu0, Double_t &thv0, Double_t &phi, TVector2 &zData, TVector3 &zError,
576 Double_t &CorrLin){
577 ///////////////////////////////////////////////////////////////////////
578 // Fit the points in the (z,s) plane - helix 3rd equation
579 //
580 ///////////////////////////////////////////////////////////////////////
581 Int_t direction=0;
d65f267e 582 //PH Double_t z[npoints],x[npoints],y[npoints],s[npoints];
583 //PH Double_t ez[npoints],ex[npoints],ey[npoints],es[npoints];
584 Double_t * z = new Double_t[npoints];
585 Double_t * x = new Double_t[npoints];
586 Double_t * y = new Double_t[npoints];
587 Double_t * s = new Double_t[npoints];
588 Double_t * ez = new Double_t[npoints];
589 Double_t * ex = new Double_t[npoints];
590 Double_t * ey = new Double_t[npoints];
591 Double_t * es = new Double_t[npoints];
8db76038 592 Double_t z0=0.0,vpar=0.0,ez0=0.0,evpar=0.0, chisquare;
593
594 // Double_t chi=TMath::Pi()/2.0+phi;
595 Double_t chi=-TMath::Pi()-phi;
596 Double_t angold=0.0, tpang=0.0;
597 for(Int_t k = 0; k<npoints; k++) {
598 x[k] = 10.0*input[k]->X(); ex[k] = 10.0*errors[k]->X();
599 y[k] = 10.0*input[k]->Y(); ey[k] = 10.0*errors[k]->Y();
600 z[k] = 10.0*input[k]->Z(); ez[k] = 10.0*errors[k]->Z();
601 if(TMath::Abs(x[k]-thu0)<1.0e-5) { // should never happen, nor give troubles...
602 chisquare=9999.99;
603 cerr<<"limit for x-x_0 "<<x[k]<<" "<<thu0<<endl;
d65f267e 604 delete [] z;
605 delete [] x;
606 delete [] y;
607 delete [] s;
608 delete [] ez;
609 delete [] ex;
610 delete [] ey;
611 delete [] es;
8db76038 612 return 12;
613 }
614 Double_t ang1=TMath::ATan2((y[k]-thv0),(x[k]-thu0));
615 if( (x[k]-thu0)<0 ) {
616 if (ang1*angold<0) {
617 tpang=ang1-TMath::Sign(TMath::Pi()*2.0,ang1);
618 ang1=tpang;
619 }
620 }
621 angold=ang1;
622 if (k>0) direction+=(z[k]>z[k-1] ? 1 : -1);
623 s[k] = (ang1+chi)/omega;
624 es[k]=TMath::Sqrt(ey[k]*ey[k]+ex[k]*ex[k]/TMath::Power((x[k]-thu0),4))*TMath::Abs(s[k]);
625 }
626 if ( TMath::Abs(direction) != (npoints-1) ) {return 11;}
627
628 TGraphErrors *fitHist = new TGraphErrors(npoints,s,z,es,ez);
629 fitHist->Fit("pol1","Q");
630 z0 = fitHist->GetFunction("pol1")->GetParameter(0);
631 vpar = fitHist->GetFunction("pol1")->GetParameter(1);
632 ez0 = fitHist->GetFunction("pol1")->GetParError(0);
633 evpar = fitHist->GetFunction("pol1")->GetParError(1);
634 chisquare = fitHist->GetFunction("pol1")->GetChisquare();
635 zData.Set(z0,vpar);
636 zError.SetXYZ(ez0,evpar,chisquare);
637
638 Double_t Sigmas=0.;
639 Double_t Sigmaz=0.;
640 Double_t Avs=0.;
641 Double_t Avz=0.;
642 Double_t Avsz=0.;
643
644 for(Int_t j = 0; j < npoints; j++) {
645 Avs += s[j];
646 Avz += z[j];
647 Avsz += s[j]*z[j];
648 }
649 Avs /= (Double_t)npoints;
650 Avz /= (Double_t)npoints;
651 Avsz /= (Double_t)npoints;
652
653 for(Int_t l = 0; l < npoints; l++) {
654 Sigmas += (s[l]-Avs)*(s[l]-Avs);
655 Sigmaz += (z[l]-Avz)*(z[l]-Avz);
656 }
657 Sigmas /=(Double_t)npoints;
658 Sigmaz /=(Double_t)npoints;
659
660 Sigmas = sqrt(Sigmas);
661 Sigmaz = sqrt(Sigmaz);
662
663 CorrLin = (Avsz-Avs*Avz)/(Sigmas*Sigmaz);
664
d65f267e 665 delete [] z;
666 delete [] x;
667 delete [] y;
668 delete [] s;
669 delete [] ez;
670 delete [] ex;
671 delete [] ey;
672 delete [] es;
673
8db76038 674 return 0;
675}
676
677//-------------------------------------------------------------------
678Int_t AliITSRiemannFit::FitHelix(Int_t tracknumber,Int_t charge,Double_t Px,Double_t Py,Double_t Pz,Double_t& fd0,
679 Double_t& fphi,Double_t& u0, Double_t& v0, Double_t& rho,Double_t& omega, Double_t& z0,
680 Double_t& vpar,Double_t& chisql, Double_t& fCorrLin,Double_t& fFit,
d65f267e 681 Int_t first,Int_t second,Int_t third,Int_t fourth,Int_t fifth,Int_t sixth) {
8db76038 682 ///////////////////////////////////////////////////////////////////////
683 // This function finds the helix paramenters
684 // d0 = impact parameter
685 // rho = radius of circle
686 // phi = atan(y0/x0)
687 // for the xy plane
688 // starting from the momentum and the outcome of
689 // the fit on the Riemann sphere (i.e. u0,v0,rho)
690 //
691 // MIND !!!! Here we assume both angular velocities be 1.0 (yes, one-dot-zero !)
692 //
693 //
694 ///////////////////////////////////////////////////////////////////////
695 //
696 // All this stuff relies on this hypothesis !!!
697 //
698// FILE *pout=fopen("chisql.dat","a");
699 Int_t ierr = 0, ierrl=0;
700 omega = 1.0e-2;
701
702 Int_t bitlay[6]={1,1,1,1,1,1};
703 bitlay[0]*=first; bitlay[1]*=second; bitlay[2]*=third; bitlay[3]*=fourth; bitlay[4]*=fifth; bitlay[5]*=sixth;
704 fd0 = -9999; // No phisycs value
705 u0 = -9999.9999; // parameters of helix - strange value...
706 v0 = -9999.9999; // parameters of helix - strange value...
707 rho = -9999.9999; // parameters of helix -unphysical strange value...
708 Int_t Layer = 0;
709 const Char_t* name = 0;
710 Int_t i=0,k=0;
711 Int_t iMAX = 50;
712 Int_t N = 0;
713 Int_t npl[6]={0,0,0,0,0,0};
714 Double_t P = sqrt(Px*Px+Py*Py+Pz*Pz);
715 Double_t Pt = sqrt(Px*Px+Py*Py);
716 TVector3 zError;
717 TVector2 zData;
718 Double_t CorrLin;
719 TVector3 *ori = new TVector3[iMAX];
720 TVector3 **original = new TVector3*[iMAX];
721 TVector3 *rie = new TVector3[iMAX];
722 TVector3 **Riemann = new TVector3*[iMAX];
723 TVector3 *err = new TVector3[iMAX];
724 TVector3 **errors = new TVector3*[iMAX];
725 TVector3 *linerr = new TVector3[iMAX];
726 TVector3 **linerrors = new TVector3*[iMAX];
d65f267e 727 //PH Double_t Weight[iMAX];
728 Double_t * Weight = new Double_t[iMAX];
8db76038 729
730 for(i=0;i<iMAX;i++){
731 original[i] = &(ori[i]);
732 Riemann[i] = &(rie[i]);
733 errors[i] = &(err[i]);
734 linerrors[i] = &(linerr[i]);
735 }
736 for(k =0;k<iMAX;k++) original[k]->SetXYZ(9999,9999,9999);
737 Double_t A11,A12,A13,A21,A22,A23,A31,A32,A33;
738 A11=0;A12=0;A13=0;A21=0;A22=0;A23=0;A31=0;A32=0;A33=0;
739 Double_t xbar = 0;
740 Double_t ybar = 0;
741 Double_t zbar = 0;
742 Double_t a,b,c,d; // cubic parameters
743 Double_t roots[3]= {0.0,0.0,0.0}; // cubic solutions
744 Double_t value = 0.0; // minimum eigenvalue
745 Double_t x1,x2,x3; // eigenvector component
746 Double_t n1,n2,n3,nr= 0;// unit eigenvector
747 Double_t Radiusdm[7] = {0.3,0.4,0.7,1.49,2.38,3.91,4.36}; // beam pipe and layers radii [dm]
748 Double_t sigma_MS = 0;
749 TVector3 Vec,VecNor;
750
751// Select RecPoints belonging to the track
752 for(k =0;k<fPoints;k++){
753 if(fPointRecs[k]->track==tracknumber) {
754 name = fPointRecs[k]->fName;
755 Pt = fPointRecs[k]->fPt;
756 Layer = fPointRecs[k]->lay;
757 Int_t ilay = Layer-1;
758 if(npl[ilay]!=0) continue;
759 if(bitlay[ilay] == 1) {
760 original[N]->SetXYZ(0.1*fPointRecs[k]->fx,0.1*fPointRecs[k]->fy,0.1*fPointRecs[k]->fz);
761 errors[N]->SetXYZ(0.1*fPointRecs[k]->fdx,0.1*fPointRecs[k]->fdy,0.1*fPointRecs[k]->fdz);
762 sigma_MS = (Radiusdm[Layer]-Radiusdm[0])*0.000724/P;// beam pipe contribution
763 for(Int_t j=1;j<Layer;j++) {
764 sigma_MS += (Radiusdm[Layer]-Radiusdm[j])*0.00136/P;
765 }
766 Weight[N] = ( 1 + original[N]->Perp2() )*( 1+ original[N]->Perp2() )/
767 ( errors[N]->Perp2() + sigma_MS*sigma_MS );
768 linerrors[N]->SetXYZ(errors[N]->X(),errors[N]->Y(),sqrt(errors[N]->Z()*errors[N]->Z()+sigma_MS*sigma_MS));
769 N++;
770 npl[ilay]++;
771 } // end if on layer
772 } //end if track==tracknumber
773 } //end for k
774 //
775 // 6 points, no more, no less
776 //
777 if(original[5]->X() == 9999 || original[6]->X() != 9999)
778 {
d65f267e 779 delete [] Weight;
8db76038 780 return 1; // not enough points
781 }
782
783 //
784 //
785 //
786 // FIT ON THE RIEMANN SPHERE FOR (x,y) PLANE
787 //
788
789 RiemannTransf(N,original,Riemann);
790
791 Double_t Sum_Weights = 0.0; // sum of weights factor
792
793 for(Int_t j=0;j<N;j++){ // mean values for x[i],y[i],z[i]
794 xbar+=Weight[j]*Riemann[j]->X();
795 ybar+=Weight[j]*Riemann[j]->Y();
796 zbar+=Weight[j]*Riemann[j]->Z();
797 Sum_Weights+=Weight[j];
798 }
799
800 xbar /= Sum_Weights;
801 ybar /= Sum_Weights;
802 zbar /= Sum_Weights;
803
804 for(Int_t j=0;j<N;j++) { // Calculate the matrix elements
805 A11 += Weight[j]*(Riemann[j]->X() - xbar)*(Riemann[j]->X() - xbar);
806 A12 += Weight[j]*(Riemann[j]->X() - xbar)*(Riemann[j]->Y() - ybar);
807 A22 += Weight[j]*(Riemann[j]->Y() - ybar)*(Riemann[j]->Y() - ybar);
808 A23 += Weight[j]*(Riemann[j]->Y() - ybar)*(Riemann[j]->Z() - zbar);
809 A13 += Weight[j]*(Riemann[j]->X() - xbar)*(Riemann[j]->Z() - zbar);
810 A33 += Weight[j]*(Riemann[j]->Z() - zbar)*(Riemann[j]->Z() - zbar);
811 }
812
813 A11 /= N;
814 A12 /= N;
815 A22 /= N;
816 A23 /= N;
817 A13 /= N;
818 A33 /= N;
819 A21 = A12;
820 A32 = A23;
821 A31 = A13;
822
823// ************** Determinant parameters ********************
824// n.b. simplifications done keeping in mind symmetry of A
825//
826 a = 1;
827 b = (-A11-A33-A22);
828 c = (A11*(A22+A33)+A33*A22-A12*A21-A13*A31-A23*A32);
829 d = (A31*A22*A13+(A12*A21-A11*A22)*A33-2.0*A23*A13*A12+A11*A23*A32);
830
831// ************** Find the 3 eigenvalues *************************
832 Int_t Check_Cubic = SolveCubic(b,c,d,roots[0],roots[1],roots[2]);
833
834 if(Check_Cubic !=1 ){
835 printf("Track %d Has no real solution continuing ...\n",tracknumber);
d65f267e 836 delete [] Weight;
8db76038 837 return 2;
838 }
839
840// **************** Find the lowest eigenvalue *****************
841 if(roots[0]<=roots[1] && roots[0]<=roots[2]) value = roots[0];
842 if(roots[1]<=roots[0] && roots[1]<=roots[2]) value = roots[1];
843 if(roots[2]<=roots[0] && roots[2]<=roots[1]) value = roots[2];
844
845 // ************ Eigenvector relative to value **************
846 x3 = 1;
847 x2 = (A33*A21-A23*A31-value*A21)/(A22*A31-A32*A21-value*A31);
848 x1 = (value-A33-A32*x2)/A31;
849 Vec.SetXYZ(x1,x2,x3);
850 VecNor = Vec.Unit();
851 n1 = VecNor.X();
852 n2 = VecNor.Y();
853 n3 = VecNor.Z();
854 nr = -n1*xbar-n2*ybar-n3*zbar;
855
856 u0 = -0.5*n1/(nr+n3);
857 v0 = -0.5*n2/(nr+n3);
858 rho = sqrt((n1*n1 + n2*n2 -4*nr*(nr+n3))/(4*(nr+n3)*(nr+n3)));
859
860 fFit = 0.0;
861 fFit += 10.*TMath::Abs(sqrt((original[0]->X()-u0)*(original[0]->X()-u0)+(original[0]->Y()-v0)*(original[0]->Y()-v0))-rho);
862 fFit += 10.*TMath::Abs(sqrt((original[1]->X()-u0)*(original[1]->X()-u0)+(original[1]->Y()-v0)*(original[1]->Y()-v0))-rho);
863 fFit += 10.*TMath::Abs(sqrt((original[2]->X()-u0)*(original[2]->X()-u0)+(original[2]->Y()-v0)*(original[2]->Y()-v0))-rho);
864 fFit += 10.*TMath::Abs(sqrt((original[3]->X()-u0)*(original[3]->X()-u0)+(original[3]->Y()-v0)*(original[3]->Y()-v0))-rho);
865 fFit += 10.*TMath::Abs(sqrt((original[4]->X()-u0)*(original[4]->X()-u0)+(original[4]->Y()-v0)*(original[4]->Y()-v0))-rho);
866 fFit += 10.*TMath::Abs(sqrt((original[5]->X()-u0)*(original[5]->X()-u0)+(original[5]->Y()-v0)*(original[5]->Y()-v0))-rho);
867
868 fd0 = 100000.*(TMath::Sqrt(u0*u0+v0*v0)-rho); // transverse impact parameter in microns
869 fphi = TMath::ATan2(v0,u0);
870
871//**************************************************************************
872// LINEAR FIT IN (z,s) PLANE: z = zData.X() + zData.Y()*s
873// strictly linear (no approximation)
874//**************************************************************************
875
876 ////////////////////////////////////////////////////////////////////////////////////////////////////////////
877 // //
878 // REMEMBER, HERE STILL LENGHTS IN DM'S FOR ___INPUT___ BUT zDATA PARAMETERS ARE RETURNED IN CM'S //
879 // rho, u0, v0 parameters converted right now to cm's... it's a mess, I'll take care, sometimes... //
880 // //
881 ////////////////////////////////////////////////////////////////////////////////////////////////////////////
882
883 rho *= 10.0;
884 u0 *= 10.0;
885 v0 *= 10.0;
886 ierrl=FitLinear(N,original,linerrors,omega,u0,v0,fphi,zData,zError,CorrLin);
887 chisql=zError.Z();
888// fprintf(pout,"%f \n",chisql);
889 z0=zData.X();
890 vpar=zData.Y();
891 fCorrLin = CorrLin;
892 ierr = (ierrl > ierr ? ierrl : ierr);
893// fclose(pout);
d65f267e 894 delete [] Weight;
8db76038 895 return ierr;
896}
897
898//-----------------------------------------------------------------------------
899void AliITSRiemannFit::Streamer(TBuffer &lRb){
900////////////////////////////////////////////////////////////////////////
901// The default Streamer function "written by ROOT" doesn't write out
902// the arrays referenced by pointers. Therefore, a specific Streamer function
903// has to be written. This function should not be modified but instead added
904// on to so that older versions can still be read.
905////////////////////////////////////////////////////////////////////////
906 // Stream an object of class AliITSRiemannFit.
907 Int_t i,j,n;
908 Int_t ii,jj;
909 n=20;
910
911 if (lRb.IsReading()) {
912 Version_t lRv = lRb.ReadVersion(); if (lRv) { }
913 TObject::Streamer(lRb);
914 lRb >> fSizeEvent;
915 lRb >> fPrimaryTracks;
916 lRb >> fPoints;
917 for(i=0;i<6;i++) lRb >> fPLay[i];
918 if(fPointRecs!=0){
919 for(i=0;i<fSizeEvent;i++) delete[] fPointRecs[i];
920 delete[] fPointRecs;
921 } // end if fPointRecs!=0
922 fPointRecs = new Point_tl*[fSizeEvent];
923 for(i=0;i<fSizeEvent;i++){
924 fPointRecs[i] = new Point_tl[n];
925 for(j=0;j<n;j++){
926 lRb >> fPointRecs[i][j].lay;
927 lRb >> fPointRecs[i][j].lad;
928 lRb >> fPointRecs[i][j].det;
929 lRb >> fPointRecs[i][j].track;
930 lRb >> fPointRecs[i][j].fx;
931 lRb >> fPointRecs[i][j].fy;
932 lRb >> fPointRecs[i][j].fz;
933 lRb >> fPointRecs[i][j].fr;
934 lRb >> fPointRecs[i][j].fdE;
935 lRb >> fPointRecs[i][j].fdx;
936 lRb >> fPointRecs[i][j].fdy;
937 lRb >> fPointRecs[i][j].fdz;
938 lRb >> fPointRecs[i][j].fPt;
939 lRb >> (Char_t*)fPointRecs[i][j].fName;
940 for (ii=0;ii<4;ii++)
941 lRb << fPointRecs[i][j].fOrigin[ii];
942 for (jj=0;jj<4;jj++)
943 lRb << fPointRecs[i][j].fMomentum[jj];
944 lRb >> fPointRecs[i][j].fCode;
945 lRb >> fPointRecs[i][j].phi;
946 lRb >> fPointRecs[i][j].eta;
947 lRb >> fPointRecs[i][j].vertexPhi;
948 } //end for j
949 } //end for i
950// if(fspdi!=0){
951// for(i=0;i<fSizeEvent/6;i++) delete[] fspdi[i];
952// delete[] fspdi;
953// } // end if fspdi!=0
954// fspdi = new Point_tl*[fSizeEvent/6];
955// for(i=0;i<fSizeEvent/6;i++){
956// fspdi[i] = new Point_tl[n];
957// for(j=0;j<n;j++){
958// lRb >> fspdi[i][j].lay;
959// lRb >> fspdi[i][j].lad;
960// lRb >> fspdi[i][j].det;
961// lRb >> fspdi[i][j].track;
962// lRb >> fspdi[i][j].fx;
963// lRb >> fspdi[i][j].fy;
964// lRb >> fspdi[i][j].fz;
965// lRb >> fspdi[i][j].fr;
966// lRb >> fspdi[i][j].fdE;
967// lRb >> fspdi[i][j].fdx;
968// lRb >> fspdi[i][j].fdy;
969// lRb >> fspdi[i][j].fdz;
970// lRb >> fspdi[i][j].fPt;
971// for (ii=0;ii<4;ii++)
972// lRb << fspdi[i][j].fOrigin[ii];
973// for (jj=0;jj<4;jj++)
974// lRb << fspdi[i][j].fMomentum[jj];
975// lRb >> fspdi[i][j].fCode;
976// lRb >> (Char_t*)fspdi[i][j].fName;
977// lRb >> fspdi[i][j].phi;
978// lRb >> fspdi[i][j].eta;
979// lRb >> fspdi[i][j].vertexPhi;
980// } //end for j
981// } //end for i
982// if(fspdo!=0){
983// for(i=0;i<fSizeEvent/6;i++) delete[] fspdo[i];
984// delete[] fspdo;
985// } // end if fspdo!=0
986// fspdo = new Point_tl*[fSizeEvent/6];
987// for(i=0;i<fSizeEvent/6;i++){
988// fspdo[i] = new Point_tl[n];
989// for(j=0;j<n;j++){
990// lRb >> fspdo[i][j].lay;
991// lRb >> fspdo[i][j].lad;
992// lRb >> fspdo[i][j].det;
993// lRb >> fspdo[i][j].track;
994// lRb >> fspdo[i][j].fx;
995// lRb >> fspdo[i][j].fy;
996// lRb >> fspdo[i][j].fz;
997// lRb >> fspdo[i][j].fr;
998// lRb >> fspdo[i][j].fdE;
999// lRb >> fspdo[i][j].fdx;
1000// lRb >> fspdo[i][j].fdy;
1001// lRb >> fspdo[i][j].fdz;
1002// lRb >> fspdo[i][j].fPt;
1003// for (ii=0;ii<4;ii++)
1004// lRb << fspdo[i][j].fOrigin[ii];
1005// for (jj=0;jj<4;jj++)
1006// lRb << fspdo[i][j].fMomentum[jj];
1007// lRb >> fspdo[i][j].fCode;
1008// lRb >> (Char_t*)fspdo[i][j].fName;
1009// lRb >> fspdo[i][j].phi;
1010// lRb >> fspdo[i][j].eta;
1011// lRb >> fspdo[i][j].vertexPhi;
1012// } //end for j
1013// } //end for i
1014 } else {
1015 lRb.WriteVersion(AliITSRiemannFit::IsA());
1016 TObject::Streamer(lRb);
1017 lRb << fSizeEvent;
1018 lRb << fPrimaryTracks;
1019 lRb << fPoints;
1020 for(i=0;i<6;i++) lRb >> fPLay[i];
1021 for(i=0;i<fSizeEvent;i++) for(j=0;j<n;j++){
1022 lRb << fPointRecs[i][j].lay;
1023 lRb << fPointRecs[i][j].lad;
1024 lRb << fPointRecs[i][j].det;
1025 lRb << fPointRecs[i][j].track;
1026 lRb << fPointRecs[i][j].fx;
1027 lRb << fPointRecs[i][j].fy;
1028 lRb << fPointRecs[i][j].fz;
1029 lRb << fPointRecs[i][j].fr;
1030 lRb << fPointRecs[i][j].fdE;
1031 lRb << fPointRecs[i][j].fdx;
1032 lRb << fPointRecs[i][j].fdy;
1033 lRb << fPointRecs[i][j].fdz;
1034 lRb << fPointRecs[i][j].fPt;
1035 for (ii=0;ii<4;ii++)
1036 lRb << fPointRecs[i][j].fOrigin[ii];
1037 for (jj=0;jj<4;jj++)
1038 lRb << fPointRecs[i][j].fMomentum[jj];
1039 lRb << fPointRecs[i][j].fCode;
1040 lRb << fPointRecs[i][j].fName;
1041 lRb << fPointRecs[i][j].phi;
1042 lRb << fPointRecs[i][j].eta;
1043 lRb << fPointRecs[i][j].vertexPhi;
1044 }
1045// for(i=0;i<fSizeEvent/6;i++) for(j=0;j<n;j++){
1046// lRb << fspdi[i][j].lay;
1047// lRb << fspdi[i][j].lad;
1048// lRb << fspdi[i][j].det;
1049// lRb << fspdi[i][j].track;
1050// lRb << fspdi[i][j].fx;
1051// lRb << fspdi[i][j].fy;
1052// lRb << fspdi[i][j].fz;
1053// lRb << fspdi[i][j].fr;
1054// lRb << fspdi[i][j].fdE;
1055// lRb << fspdi[i][j].fdx;
1056// lRb << fspdi[i][j].fdy;
1057// lRb << fspdi[i][j].fdz;
1058// lRb << fspdi[i][j].fPt;
1059// for (ii=0;ii<4;ii++)
1060// lRb << fspdi[i][j].fOrigin[ii];
1061// for (jj=0;jj<4;jj++)
1062// lRb << fspdi[i][j].fMomentum[jj];
1063// lRb << fspdi[i][j].fCode;
1064// lRb << fspdi[i][j].fName;
1065// lRb << fspdi[i][j].phi;
1066// lRb << fspdi[i][j].eta;
1067// lRb << fspdi[i][j].vertexPhi;
1068// }
1069// for(i=0;i<fSizeEvent/6;i++) for(j=0;j<n;j++){
1070// lRb << fspdo[i][j].lay;
1071// lRb << fspdo[i][j].lad;
1072// lRb << fspdo[i][j].det;
1073// lRb << fspdo[i][j].track;
1074// lRb << fspdo[i][j].fx;
1075// lRb << fspdo[i][j].fy;
1076// lRb << fspdo[i][j].fz;
1077// lRb << fspdo[i][j].fr;
1078// lRb << fspdo[i][j].fdE;
1079// lRb << fspdo[i][j].fdx;
1080// lRb << fspdo[i][j].fdy;
1081// lRb << fspdo[i][j].fdz;
1082// lRb << fspdo[i][j].fPt;
1083// for (ii=0;ii<4;ii++)
1084// lRb << fspdo[i][j].fOrigin[ii];
1085// for (jj=0;jj<4;jj++)
1086// lRb << fspdo[i][j].fMomentum[jj];
1087// lRb << fspdo[i][j].fCode;
1088// lRb << fspdo[i][j].fName;
1089// lRb << fspdo[i][j].phi;
1090// lRb << fspdo[i][j].eta;
1091// lRb << fspdo[i][j].vertexPhi;
1092// }
1093 } // end if reading
1094}