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 **************************************************************************/
16 //-----------------------------------------------------------------
17 // Implementation of the derived class for track residuals
18 // based on Chi2 minimization
20 //-----------------------------------------------------------------
22 #include <TVirtualFitter.h>
23 #include <TGeoMatrix.h>
25 #include "AliAlignObj.h"
26 #include "AliTrackPointArray.h"
27 #include "AliTrackResidualsChi2.h"
29 void Fcn(Int_t &npar, Double_t *gin, Double_t &f, Double_t *x, Int_t iflag);
32 ClassImp(AliTrackResidualsChi2)
35 //______________________________________________________________________________
36 void Fcn(Int_t &npar, Double_t *gin, Double_t &f, Double_t *par, Int_t iflag)
38 // This function is called by minuit
39 // The corresponding member method is called
40 // using SetObjectFit/GetObjectFit methods of TMinuit
41 AliTrackResidualsChi2* dummy = (AliTrackResidualsChi2 *)TVirtualFitter::GetFitter()->GetObjectFit();
42 dummy->Chi2(npar, gin, f, par, iflag);
45 //______________________________________________________________________________
46 Bool_t AliTrackResidualsChi2::Minimize()
48 // Implementation of Chi2 based minimization
49 // of track residuala sum
51 // CHOLM: Modified to use the TVirtualFitter interface only. This
52 // makes it possible other fitters than TMinuit (say TMinuit2,
53 // TFumili) by simply changing ones configuration file, or setting
54 // it up in a script. Much more robust and flexible.
57 TVirtualFitter *fitter = TVirtualFitter::Fitter(this,6); //initialize TMinuit
59 ierflg = fitter->ExecuteCommand("SET PRINT", arglist, 1);
64 ierflg = fitter->ExecuteCommand("SET ERR", arglist ,1);
66 // Set starting values and step sizes for parameters
67 Double_t pars[6] = {0,0,0,0,0,0};
68 Double_t step[6] = {0.0001,0.0001,0.0001,0.0001,0.0001,0.0001};
69 ierflg = fitter->SetParameter(0, "dx", pars[0], step[0], 0,0);
70 ierflg = fitter->SetParameter(1, "dy", pars[1], step[1], 0,0);
71 ierflg = fitter->SetParameter(2, "dz", pars[2], step[2], 0,0);
72 ierflg = fitter->SetParameter(3, "psi", pars[3], step[3], 0,0);
73 ierflg = fitter->SetParameter(4, "theta", pars[4], step[4], 0,0);
74 ierflg = fitter->SetParameter(5, "phi", pars[5], step[5], 0,0);
76 // Now ready for minimization step
79 fitter->ExecuteCommand("MIGRAD", arglist ,2);
82 Double_t amin,edm,errdef;
83 Int_t nvpar,nparx,icstat;
84 icstat = fitter->GetStats(amin,edm,errdef,nvpar,nparx);
85 fChi2 = amin; fNdf -= nvpar;
90 //______________________________________________________________________________
91 void AliTrackResidualsChi2::Chi2(Int_t & /* npar */, Double_t * /* gin */, Double_t &f, Double_t *par, Int_t /* iflag */)
93 // Chi2 function to be minimized
94 // Sums all the track residuals
97 fAlignObj->SetPars(par[0],par[1],par[2],par[3],par[4],par[5]);
101 Bool_t count = kFALSE;
102 if (fNdf == 0) count = kTRUE;
104 for (Int_t itrack = 0; itrack < fLast; itrack++) {
105 if (!fVolArray[itrack] || !fTrackArray[itrack]) continue;
106 for (Int_t ipoint = 0; ipoint < fVolArray[itrack]->GetNPoints(); ipoint++) {
107 fVolArray[itrack]->GetPoint(p1,ipoint);
108 fAlignObj->Transform(p1);
109 fTrackArray[itrack]->GetPoint(p2,ipoint);
110 Float_t residual = p2.GetResidual(p1,kTRUE);
112 if (count) fNdf += 3;