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 ///////////////////////////////////////////////////////////////////////////
95 ClassImp(AliJet) // Class implementation to enable ROOT I/O
99 // Default constructor
100 // All variables initialised to 0
101 // Initial maximum number of tracks is set to the default value
106 ///////////////////////////////////////////////////////////////////////////
109 // Initialisation of pointers etc...
114 ///////////////////////////////////////////////////////////////////////////
115 AliJet::AliJet(Int_t n)
117 // Create a jet to hold initially a maximum of n tracks
118 // All variables initialised to 0
128 cout << " *AliJet* Initial max. number of tracks entered : " << n << endl;
129 cout << " This is invalid. Default initial maximum will be used." << endl;
134 ///////////////////////////////////////////////////////////////////////////
137 // Default destructor
144 ///////////////////////////////////////////////////////////////////////////
145 void AliJet::SetOwner(Bool_t own)
147 // Set ownership of all added objects.
148 // The default parameter is own=kTRUE.
150 // Invokation of this memberfunction also sets all the copy modes
151 // (e.g. TrackCopy & co.) according to the value of own.
153 // This function (with own=kTRUE) is particularly useful when reading data
154 // from a tree/file, since Reset() will then actually remove all the
155 // added objects from memory irrespective of the copy mode settings
156 // during the tree/file creation process. In this way it provides a nice way
157 // of preventing possible memory leaks in the reading/analysis process.
159 // In addition this memberfunction can also be used as a shortcut to set all
160 // copy modes in one go during a tree/file creation process.
161 // However, in this case the user has to take care to only set/change the
162 // ownership (and copy mode) for empty objects (e.g. newly created objects
163 // or after invokation of the Reset() memberfunction) otherwise it will
164 // very likely result in inconsistent destructor behaviour.
168 if (fTracks) fTracks->SetOwner(own);
171 ///////////////////////////////////////////////////////////////////////////
172 AliJet::AliJet(AliJet& j)
178 SetTrackCopy(j.GetTrackCopy());
182 for (Int_t i=1; i<=j.GetNtracks(); i++)
185 if (tx) AddTrack(tx);
188 ///////////////////////////////////////////////////////////////////////////
189 void AliJet::SetNtinit(Int_t n)
191 // Set the initial maximum number of tracks for this jet
200 ///////////////////////////////////////////////////////////////////////////
203 // Reset all variables to 0
204 // The max. number of tracks is set to the initial value again
208 Double_t a[4]={0,0,0,0};
210 if (fNtinit > 0) SetNtinit(fNtinit);
212 ///////////////////////////////////////////////////////////////////////////
213 void AliJet::AddTrack(AliTrack& t,Int_t copy)
215 // Add a track to the jet.
216 // Note : The optional parameter "copy" is for internal use only.
217 // In case the maximum number of tracks has been reached
218 // space will be extended to hold an additional amount of tracks as
219 // was initially reserved.
222 fTracks=new TObjArray(fNtmax);
223 if (fTrackCopy) fTracks->SetOwner();
225 if (fNtrk == fNtmax) // Check if maximum track number is reached
228 fTracks->Expand(fNtmax);
231 // Add the track to this jet
233 if (fTrackCopy && copy)
235 fTracks->Add(new AliTrack(t));
242 (*this)+=(Ali4Vector&)t;
246 ///////////////////////////////////////////////////////////////////////////
247 void AliJet::Data(TString f)
249 // Provide jet information within the coordinate frame f
250 cout << " *AliJet::Data* Id : " << fUserId << " Invmass : " << GetInvmass() << " Charge : " << fQ
251 << " Momentum : " << GetMomentum() << " Ntracks : " << fNtrk << endl;
255 ///////////////////////////////////////////////////////////////////////////
256 void AliJet::List(TString f)
258 // Provide jet and primary track information within the coordinate frame f
260 Data(f); // Information of the current jet
262 // The tracks of this jet
264 for (Int_t it=1; it<=fNtrk; it++)
269 cout << " ---Track no. " << it << endl;
275 cout << " *AliJet::List* Error : No track present." << endl;
279 ///////////////////////////////////////////////////////////////////////////
280 void AliJet::ListAll(TString f)
282 // Provide jet and prim.+sec. track information within the coordinate frame f
284 Data(f); // Information of the current jet
286 // The tracks of this jet
288 for (Int_t it=1; it<=fNtrk; it++)
293 cout << " ---Track no. " << it << endl;
299 cout << " *AliJet::List* Error : No track present." << endl;
303 ///////////////////////////////////////////////////////////////////////////
304 Int_t AliJet::GetNtracks()
306 // Return the current number of tracks of this jet
309 ///////////////////////////////////////////////////////////////////////////
310 Double_t AliJet::GetEnergy()
312 // Return the total energy of the jet
315 ///////////////////////////////////////////////////////////////////////////
316 Double_t AliJet::GetMomentum()
318 // Return the value of the total jet 3-momentum
319 // The error can be obtained by invoking GetResultError() after
320 // invokation of GetMomentum().
321 Double_t norm=fV.GetNorm();
322 fDresult=fV.GetResultError();
325 ///////////////////////////////////////////////////////////////////////////
326 Ali3Vector AliJet::Get3Momentum()
328 // Return the the total jet 3-momentum
329 Ali3Vector p=Get3Vector();
332 ///////////////////////////////////////////////////////////////////////////
333 Double_t AliJet::GetInvmass()
335 // Return the invariant mass of the jet
336 Double_t m2=Dot(*this);
346 ///////////////////////////////////////////////////////////////////////////
347 Float_t AliJet::GetCharge()
349 // Return the total charge of the jet
352 ///////////////////////////////////////////////////////////////////////////
353 AliTrack* AliJet::GetTrack(Int_t i)
355 // Return the i-th track of this jet
358 cout << " *AliJet*::GetTrack* No tracks present." << endl;
365 cout << " *AliJet*::GetTrack* Invalid argument i : " << i
366 << " Ntrk = " << fNtrk << endl;
371 return (AliTrack*)fTracks->At(i-1);
375 ///////////////////////////////////////////////////////////////////////////
376 AliTrack* AliJet::GetIdTrack(Int_t id)
378 // Return the track with user identifier "id" of this jet
383 cout << " *AliJet*::GetIdTrack* No tracks present." << endl;
388 for (Int_t i=0; i<fNtrk; i++)
390 tx=(AliTrack*)fTracks->At(i);
391 if (id == tx->GetId()) t=tx;
396 ///////////////////////////////////////////////////////////////////////////
397 Double_t AliJet::GetPt()
399 // Provide trans. momentum value w.r.t. z-axis.
400 // The error on the value can be obtained by GetResultError()
401 // after invokation of GetPt().
404 Double_t norm=v.GetNorm();
405 fDresult=v.GetResultError();
409 ///////////////////////////////////////////////////////////////////////////
410 Double_t AliJet::GetPl()
412 // Provide long. momentum value w.r.t. z-axis.
413 // Note : the returned value can also be negative.
414 // The error on the value can be obtained by GetResultError()
415 // after invokation of GetPl().
419 Double_t pl=v.GetNorm();
420 fDresult=v.GetResultError();
423 v.GetVector(a,"sph");
424 if (cos(a[1])<0) pl=-pl;
428 ///////////////////////////////////////////////////////////////////////////
429 Double_t AliJet::GetEt()
431 // Provide trans. energy value w.r.t. z-axis.
432 // The error on the value can be obtained by GetResultError()
433 // after invokation of GetEt().
434 Double_t et=GetScaTrans();
438 ///////////////////////////////////////////////////////////////////////////
439 Double_t AliJet::GetEl()
441 // Provide long. energy value w.r.t. z-axis.
442 // Note : the returned value can also be negative.
443 // The error on the value can be obtained by GetResultError()
444 // after invokation of GetEl().
445 Double_t el=GetScaLong();
449 ///////////////////////////////////////////////////////////////////////////
450 Double_t AliJet::GetMt()
452 // Provide transverse mass value w.r.t. z-axis.
453 // The error on the value can be obtained by GetResultError()
454 // after invokation of GetMt().
456 Double_t dpt=GetResultError();
457 Double_t m=GetInvmass();
458 Double_t dm=GetResultError();
460 Double_t mt=sqrt(pt*pt+m*m);
462 if (mt) dmt2=(pow((pt*dpt),2)+pow((m*dm),2))/(mt*mt);
467 ///////////////////////////////////////////////////////////////////////////
468 Double_t AliJet::GetRapidity()
470 // Provide rapidity value w.r.t. z-axis.
471 // The error on the value can be obtained by GetResultError()
472 // after invokation of GetRapidity().
473 // Note : Also GetPseudoRapidity() is available since this class is
474 // derived from Ali4Vector.
475 Double_t e=GetEnergy();
476 Double_t de=GetResultError();
478 Double_t dpl=GetResultError();
482 Double_t y=9999,dy2=0;
483 if (sum && dif) y=0.5*log(sum/dif);
485 if (sum*dif) dy2=(1./(sum*dif))*(pow((pl*de),2)+pow((e*dpl),2));
490 ///////////////////////////////////////////////////////////////////////////
491 void AliJet::SetTrackCopy(Int_t j)
493 // (De)activate the creation of private copies of the added tracks.
494 // j=0 ==> No private copies are made; pointers of original tracks are stored.
495 // j=1 ==> Private copies of the tracks are made and these pointers are stored.
497 // Note : Once the storage contains pointer(s) to AliTrack(s) one cannot
498 // change the TrackCopy mode anymore.
499 // To change the TrackCopy mode for an existing AliJet containing
500 // tracks one first has to invoke Reset().
509 cout << "*AliJet::SetTrackCopy* Invalid argument : " << j << endl;
514 cout << "*AliJet::SetTrackCopy* Storage already contained tracks."
515 << " ==> TrackCopy mode not changed." << endl;
518 ///////////////////////////////////////////////////////////////////////////
519 Int_t AliJet::GetTrackCopy()
521 // Provide value of the TrackCopy mode.
522 // 0 ==> No private copies are made; pointers of original tracks are stored.
523 // 1 ==> Private copies of the tracks are made and these pointers are stored.
526 ///////////////////////////////////////////////////////////////////////////
527 void AliJet::SetId(Int_t id)
529 // Set a user defined identifier for this jet.
532 ///////////////////////////////////////////////////////////////////////////
533 Int_t AliJet::GetId()
535 // Provide the user defined identifier of this jet.
538 ///////////////////////////////////////////////////////////////////////////