1 /**************************************************************************
2 * Copyright(c) 1998-1999, ALICE Experiment at CERN, All rights reserved. *
4 * Author: The ALICE Off-line Project. *
5 * Contributors are mentioned in the code where appropriate. *
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 **************************************************************************/
18 ///////////////////////////////////////////////////////////////////////////
20 // Creation and investigation of a jet of particle tracks.
21 // An AliJet can be constructed by adding AliTracks.
23 // To provide maximal flexibility to the user, two modes of track storage
24 // are provided by means of the memberfunction SetTrackCopy().
26 // a) SetTrackCopy(0) (which is the default).
27 // Only the pointers of the 'added' tracks are stored.
28 // This mode is typically used by making jet studies based on a fixed list
29 // of tracks which stays under user control or is contained for instance
31 // In this way the AliJet just represents a 'logical structure' for the
32 // physics analysis which can be embedded in e.g. an AliEvent or AliVertex.
35 // Modifications made to the original tracks also affect the AliTrack objects
36 // which are stored in the AliJet.
38 // b) SetTrackCopy(1).
39 // Of every 'added' track a private copy will be made of which the pointer
41 // In this way the AliJet represents an entity on its own and modifications
42 // made to the original tracks do not affect the AliTrack objects which are
43 // stored in the AliJet.
44 // This mode will allow 'adding' many different AliTracks into an AliJet by
45 // creating only one AliTrack instance in the main programme and using the
46 // AliTrack::Reset() and AliTrack parameter setting memberfunctions.
48 // See also the documentation provided for the memberfunction SetOwner().
50 // Coding example to make 2 jets j1 and j2.
51 // ----------------------------------------
52 // j1 contains the AliTracks t1 and t2
53 // j2 contains 10 different AliTracks via tx
57 // ... // code to fill the AliTrack data
64 // j2.SetTrackCopy(1);
65 // AliTrack* tx=new AliTrack();
66 // for (Int_t i=0; i<10; i++)
69 // ... // code to set momentum etc... of the track tx
78 // Float_t e1=j1.GetEnergy();
79 // Float_t pnorm=j1->GetMomentum();
80 // Ali3Vector p=j1->Get3Momentum();
81 // Float_t m=j1.GetInvmass();
82 // Int_t ntk=j1.GetNtracks();
83 // AliTrack* tj=j1.GetTrack(1);
87 // Note : All quantities are in GeV, GeV/c or GeV/c**2
89 //--- Author: Nick van Eijndhoven 10-jul-1997 UU-SAP Utrecht
90 //- Modified: NvE $Date$ UU-SAP Utrecht
91 ///////////////////////////////////////////////////////////////////////////
94 #include "Riostream.h"
96 ClassImp(AliJet) // Class implementation to enable ROOT I/O
98 AliJet::AliJet() : TObject(),Ali4Vector()
100 // Default constructor
101 // All variables initialised to 0
102 // Initial maximum number of tracks is set to the default value
107 ///////////////////////////////////////////////////////////////////////////
110 // Initialisation of pointers etc...
115 ///////////////////////////////////////////////////////////////////////////
116 AliJet::AliJet(Int_t n) : TObject(),Ali4Vector()
118 // Create a jet to hold initially a maximum of n tracks
119 // All variables initialised to 0
129 cout << " *AliJet* Initial max. number of tracks entered : " << n << endl;
130 cout << " This is invalid. Default initial maximum will be used." << endl;
135 ///////////////////////////////////////////////////////////////////////////
138 // Default destructor
145 ///////////////////////////////////////////////////////////////////////////
146 void AliJet::SetOwner(Bool_t own)
148 // Set ownership of all added objects.
149 // The default parameter is own=kTRUE.
151 // Invokation of this memberfunction also sets all the copy modes
152 // (e.g. TrackCopy & co.) according to the value of own.
154 // This function (with own=kTRUE) is particularly useful when reading data
155 // from a tree/file, since Reset() will then actually remove all the
156 // added objects from memory irrespective of the copy mode settings
157 // during the tree/file creation process. In this way it provides a nice way
158 // of preventing possible memory leaks in the reading/analysis process.
160 // In addition this memberfunction can also be used as a shortcut to set all
161 // copy modes in one go during a tree/file creation process.
162 // However, in this case the user has to take care to only set/change the
163 // ownership (and copy mode) for empty objects (e.g. newly created objects
164 // or after invokation of the Reset() memberfunction) otherwise it will
165 // very likely result in inconsistent destructor behaviour.
169 if (fTracks) fTracks->SetOwner(own);
172 ///////////////////////////////////////////////////////////////////////////
173 AliJet::AliJet(AliJet& j) : TObject(j),Ali4Vector(j)
180 fTrackCopy=j.fTrackCopy;
186 fTracks=new TObjArray(fNtmax);
187 if (fTrackCopy) fTracks->SetOwner();
190 for (Int_t i=1; i<=fNtrk; i++)
192 AliTrack* tx=j.GetTrack(i);
195 fTracks->Add(new AliTrack(*tx));
203 ///////////////////////////////////////////////////////////////////////////
204 void AliJet::SetNtinit(Int_t n)
206 // Set the initial maximum number of tracks for this jet
215 ///////////////////////////////////////////////////////////////////////////
218 // Reset all variables to 0
219 // The max. number of tracks is set to the initial value again
223 Double_t a[4]={0,0,0,0};
225 if (fNtinit > 0) SetNtinit(fNtinit);
227 ///////////////////////////////////////////////////////////////////////////
228 void AliJet::AddTrack(AliTrack& t,Int_t copy)
230 // Add a track to the jet.
231 // Note : The optional parameter "copy" is for internal use only.
232 // In case the maximum number of tracks has been reached
233 // space will be extended to hold an additional amount of tracks as
234 // was initially reserved.
237 fTracks=new TObjArray(fNtmax);
238 if (fTrackCopy) fTracks->SetOwner();
240 if (fNtrk == fNtmax) // Check if maximum track number is reached
243 fTracks->Expand(fNtmax);
246 // Add the track to this jet
248 if (fTrackCopy && copy)
250 fTracks->Add(new AliTrack(t));
257 (*this)+=(Ali4Vector&)t;
261 ///////////////////////////////////////////////////////////////////////////
262 void AliJet::Data(TString f)
264 // Provide jet information within the coordinate frame f
265 cout << " *AliJet::Data* Id : " << fUserId << " Invmass : " << GetInvmass() << " Charge : " << fQ
266 << " Momentum : " << GetMomentum() << " Ntracks : " << fNtrk << endl;
270 ///////////////////////////////////////////////////////////////////////////
271 void AliJet::List(TString f)
273 // Provide jet and primary track information within the coordinate frame f
275 Data(f); // Information of the current jet
277 // The tracks of this jet
279 for (Int_t it=1; it<=fNtrk; it++)
284 cout << " ---Track no. " << it << endl;
290 cout << " *AliJet::List* Error : No track present." << endl;
294 ///////////////////////////////////////////////////////////////////////////
295 void AliJet::ListAll(TString f)
297 // Provide jet and prim.+sec. track information within the coordinate frame f
299 Data(f); // Information of the current jet
301 // The tracks of this jet
303 for (Int_t it=1; it<=fNtrk; it++)
308 cout << " ---Track no. " << it << endl;
314 cout << " *AliJet::List* Error : No track present." << endl;
318 ///////////////////////////////////////////////////////////////////////////
319 Int_t AliJet::GetNtracks()
321 // Return the current number of tracks of this jet
324 ///////////////////////////////////////////////////////////////////////////
325 Double_t AliJet::GetEnergy()
327 // Return the total energy of the jet
330 ///////////////////////////////////////////////////////////////////////////
331 Double_t AliJet::GetMomentum()
333 // Return the value of the total jet 3-momentum
334 // The error can be obtained by invoking GetResultError() after
335 // invokation of GetMomentum().
336 Double_t norm=fV.GetNorm();
337 fDresult=fV.GetResultError();
340 ///////////////////////////////////////////////////////////////////////////
341 Ali3Vector AliJet::Get3Momentum()
343 // Return the the total jet 3-momentum
344 Ali3Vector p=Get3Vector();
347 ///////////////////////////////////////////////////////////////////////////
348 Double_t AliJet::GetInvmass()
350 // Return the invariant mass of the jet
351 Double_t m2=Dot(*this);
361 ///////////////////////////////////////////////////////////////////////////
362 Float_t AliJet::GetCharge()
364 // Return the total charge of the jet
367 ///////////////////////////////////////////////////////////////////////////
368 AliTrack* AliJet::GetTrack(Int_t i)
370 // Return the i-th track of this jet
373 cout << " *AliJet*::GetTrack* No tracks present." << endl;
380 cout << " *AliJet*::GetTrack* Invalid argument i : " << i
381 << " Ntrk = " << fNtrk << endl;
386 return (AliTrack*)fTracks->At(i-1);
390 ///////////////////////////////////////////////////////////////////////////
391 AliTrack* AliJet::GetIdTrack(Int_t id)
393 // Return the track with user identifier "id" of this jet
398 cout << " *AliJet*::GetIdTrack* No tracks present." << endl;
403 for (Int_t i=0; i<fNtrk; i++)
405 tx=(AliTrack*)fTracks->At(i);
406 if (id == tx->GetId()) t=tx;
411 ///////////////////////////////////////////////////////////////////////////
412 Double_t AliJet::GetPt()
414 // Provide trans. momentum value w.r.t. z-axis.
415 // The error on the value can be obtained by GetResultError()
416 // after invokation of GetPt().
419 Double_t norm=v.GetNorm();
420 fDresult=v.GetResultError();
424 ///////////////////////////////////////////////////////////////////////////
425 Double_t AliJet::GetPl()
427 // Provide long. momentum value w.r.t. z-axis.
428 // Note : the returned value can also be negative.
429 // The error on the value can be obtained by GetResultError()
430 // after invokation of GetPl().
434 Double_t pl=v.GetNorm();
435 fDresult=v.GetResultError();
438 v.GetVector(a,"sph");
439 if (cos(a[1])<0) pl=-pl;
443 ///////////////////////////////////////////////////////////////////////////
444 Double_t AliJet::GetEt()
446 // Provide trans. energy value w.r.t. z-axis.
447 // The error on the value can be obtained by GetResultError()
448 // after invokation of GetEt().
449 Double_t et=GetScaTrans();
453 ///////////////////////////////////////////////////////////////////////////
454 Double_t AliJet::GetEl()
456 // Provide long. energy value w.r.t. z-axis.
457 // Note : the returned value can also be negative.
458 // The error on the value can be obtained by GetResultError()
459 // after invokation of GetEl().
460 Double_t el=GetScaLong();
464 ///////////////////////////////////////////////////////////////////////////
465 Double_t AliJet::GetMt()
467 // Provide transverse mass value w.r.t. z-axis.
468 // The error on the value can be obtained by GetResultError()
469 // after invokation of GetMt().
471 Double_t dpt=GetResultError();
472 Double_t m=GetInvmass();
473 Double_t dm=GetResultError();
475 Double_t mt=sqrt(pt*pt+m*m);
477 if (mt) dmt2=(pow((pt*dpt),2)+pow((m*dm),2))/(mt*mt);
482 ///////////////////////////////////////////////////////////////////////////
483 Double_t AliJet::GetRapidity()
485 // Provide rapidity value w.r.t. z-axis.
486 // The error on the value can be obtained by GetResultError()
487 // after invokation of GetRapidity().
488 // Note : Also GetPseudoRapidity() is available since this class is
489 // derived from Ali4Vector.
490 Double_t e=GetEnergy();
491 Double_t de=GetResultError();
493 Double_t dpl=GetResultError();
497 Double_t y=9999,dy2=0;
498 if (sum && dif) y=0.5*log(sum/dif);
500 if (sum*dif) dy2=(1./(sum*dif))*(pow((pl*de),2)+pow((e*dpl),2));
505 ///////////////////////////////////////////////////////////////////////////
506 void AliJet::SetTrackCopy(Int_t j)
508 // (De)activate the creation of private copies of the added tracks.
509 // j=0 ==> No private copies are made; pointers of original tracks are stored.
510 // j=1 ==> Private copies of the tracks are made and these pointers are stored.
512 // Note : Once the storage contains pointer(s) to AliTrack(s) one cannot
513 // change the TrackCopy mode anymore.
514 // To change the TrackCopy mode for an existing AliJet containing
515 // tracks one first has to invoke Reset().
524 cout << "*AliJet::SetTrackCopy* Invalid argument : " << j << endl;
529 cout << "*AliJet::SetTrackCopy* Storage already contained tracks."
530 << " ==> TrackCopy mode not changed." << endl;
533 ///////////////////////////////////////////////////////////////////////////
534 Int_t AliJet::GetTrackCopy()
536 // Provide value of the TrackCopy mode.
537 // 0 ==> No private copies are made; pointers of original tracks are stored.
538 // 1 ==> Private copies of the tracks are made and these pointers are stored.
541 ///////////////////////////////////////////////////////////////////////////
542 void AliJet::SetId(Int_t id)
544 // Set a user defined identifier for this jet.
547 ///////////////////////////////////////////////////////////////////////////
548 Int_t AliJet::GetId()
550 // Provide the user defined identifier of this jet.
553 ///////////////////////////////////////////////////////////////////////////