]>
Commit | Line | Data |
---|---|---|
98937d93 | 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 | // Implementation of the derived class for track residuals | |
18 | // based on Chi2 minimization | |
19 | // | |
20 | //----------------------------------------------------------------- | |
21 | ||
22 | #include <TMinuit.h> | |
23 | #include <TGeoMatrix.h> | |
24 | ||
25 | #include "AliAlignObj.h" | |
26 | #include "AliTrackPointArray.h" | |
27 | #include "AliTrackResidualsChi2.h" | |
28 | ||
46ae650f | 29 | void Fcn(Int_t &npar, Double_t *gin, Double_t &f, Double_t *x, Int_t iflag); |
30 | ||
98937d93 | 31 | ClassImp(AliTrackResidualsChi2) |
32 | ||
33 | //______________________________________________________________________________ | |
34 | void Fcn(Int_t &npar, Double_t *gin, Double_t &f, Double_t *par, Int_t iflag) | |
35 | { | |
36 | // This function is called by minuit | |
37 | // The corresponding member method is called | |
38 | // using SetObjectFit/GetObjectFit methods of TMinuit | |
39 | AliTrackResidualsChi2* dummy = (AliTrackResidualsChi2 *)gMinuit->GetObjectFit(); | |
40 | dummy->Chi2(npar, gin, f, par, iflag); | |
41 | } | |
42 | ||
43 | //______________________________________________________________________________ | |
44 | Bool_t AliTrackResidualsChi2::Minimize() | |
45 | { | |
46 | // Implementation of Chi2 based minimization | |
47 | // of track residuala sum | |
46ae650f | 48 | Double_t arglist[10]; |
49 | Int_t ierflg = 0; | |
98937d93 | 50 | TMinuit *gMinuit = new TMinuit(6); //initialize TMinuit |
46ae650f | 51 | arglist[0] = -1; |
52 | gMinuit->mnexcm("SET PRINT", arglist, 1, ierflg); | |
53 | ||
98937d93 | 54 | gMinuit->SetObjectFit(this); |
55 | gMinuit->SetFCN(Fcn); | |
56 | ||
98937d93 | 57 | arglist[0] = 1; |
58 | gMinuit->mnexcm("SET ERR", arglist ,1,ierflg); | |
59 | ||
60 | // Set starting values and step sizes for parameters | |
46ae650f | 61 | Double_t pars[6] = {0,0,0,0,0,0}; |
62 | Double_t step[6] = {0.0001,0.0001,0.0001,0.0001,0.0001,0.0001}; | |
63 | gMinuit->mnparm(0, "dx", pars[0], step[0], 0,0,ierflg); | |
64 | gMinuit->mnparm(1, "dy", pars[1], step[1], 0,0,ierflg); | |
65 | gMinuit->mnparm(2, "dz", pars[2], step[2], 0,0,ierflg); | |
66 | gMinuit->mnparm(3, "psi", pars[3], step[3], 0,0,ierflg); | |
67 | gMinuit->mnparm(4, "theta", pars[4], step[4], 0,0,ierflg); | |
68 | gMinuit->mnparm(5, "phi", pars[5], step[5], 0,0,ierflg); | |
98937d93 | 69 | |
70 | // Now ready for minimization step | |
71 | arglist[0] = 500; | |
72 | arglist[1] = 1.; | |
73 | gMinuit->mnexcm("MIGRAD", arglist ,2,ierflg); | |
74 | ||
75 | // Print results | |
76 | Double_t amin,edm,errdef; | |
77 | Int_t nvpar,nparx,icstat; | |
78 | gMinuit->mnstat(amin,edm,errdef,nvpar,nparx,icstat); | |
46ae650f | 79 | fChi2 = amin; fNdf -= nvpar; |
98937d93 | 80 | |
81 | return kTRUE; | |
82 | } | |
83 | ||
84 | //______________________________________________________________________________ | |
85 | void AliTrackResidualsChi2::Chi2(Int_t & /* npar */, Double_t * /* gin */, Double_t &f, Double_t *par, Int_t /* iflag */) | |
86 | { | |
87 | // Chi2 function to be minimized | |
88 | // Sums all the track residuals | |
89 | Double_t chi2 = 0; | |
90 | ||
91 | fAlignObj->SetPars(par[0],par[1],par[2],par[3],par[4],par[5]); | |
98937d93 | 92 | |
93 | AliTrackPoint p1,p2; | |
46ae650f | 94 | |
95 | Bool_t count = kFALSE; | |
96 | if (fNdf == 0) count = kTRUE; | |
98937d93 | 97 | |
98 | for (Int_t itrack = 0; itrack < fLast; itrack++) { | |
99 | if (!fVolArray[itrack] || !fTrackArray[itrack]) continue; | |
100 | for (Int_t ipoint = 0; ipoint < fVolArray[itrack]->GetNPoints(); ipoint++) { | |
101 | fVolArray[itrack]->GetPoint(p1,ipoint); | |
46ae650f | 102 | fAlignObj->Transform(p1); |
98937d93 | 103 | fTrackArray[itrack]->GetPoint(p2,ipoint); |
cc345ce3 | 104 | Float_t residual = p2.GetResidual(p1,kTRUE); |
46ae650f | 105 | chi2 += residual; |
106 | if (count) fNdf += 3; | |
98937d93 | 107 | } |
108 | } | |
109 | f = chi2; | |
110 | } |