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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 <TVirtualFitter.h> | |
23 | #include <TGeoMatrix.h> | |
24 | ||
25 | #include "AliAlignObj.h" | |
26 | #include "AliTrackPointArray.h" | |
27 | #include "AliTrackResidualsChi2.h" | |
28 | ||
29 | void TrackResidualsChi2Fcn(Int_t &npar, Double_t *gin, Double_t &f, Double_t *x, Int_t iflag); | |
30 | ||
31 | ||
32 | ClassImp(AliTrackResidualsChi2) | |
33 | ||
34 | ||
35 | //______________________________________________________________________________ | |
36 | void TrackResidualsChi2Fcn(Int_t &npar, Double_t *gin, Double_t &f, Double_t *par, Int_t iflag) | |
37 | { | |
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); | |
43 | } | |
44 | ||
45 | //______________________________________________________________________________ | |
46 | Bool_t AliTrackResidualsChi2::Minimize() | |
47 | { | |
48 | // Implementation of Chi2 based minimization | |
49 | // of track residuala sum | |
50 | // | |
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. | |
55 | Double_t arglist[10]; | |
56 | Int_t ierflg = 0; | |
57 | TVirtualFitter *fitter = TVirtualFitter::Fitter(this,6); //initialize TMinuit | |
58 | arglist[0] = -1; | |
59 | ierflg = fitter->ExecuteCommand("SET PRINT", arglist, 1); | |
60 | ||
61 | fitter->SetFCN(TrackResidualsChi2Fcn); | |
62 | ||
63 | arglist[0] = 1; | |
64 | ierflg = fitter->ExecuteCommand("SET ERR", arglist ,1); | |
65 | ||
66 | // Set starting values and step sizes for parameters | |
67 | Double_t pars[6] = {0,0,0,0,0,0}; | |
68 | for(Int_t i=0;i<6;i++) if(fBFixed[i]) pars[i]=fFixed[i]; | |
69 | Double_t step[6] = {0.0001,0.0001,0.0001,0.0001,0.0001,0.0001}; | |
70 | ierflg = fitter->SetParameter(0, "dx", pars[0], step[0], 0,0); | |
71 | ierflg = fitter->SetParameter(1, "dy", pars[1], step[1], 0,0); | |
72 | ierflg = fitter->SetParameter(2, "dz", pars[2], step[2], 0,0); | |
73 | ierflg = fitter->SetParameter(3, "psi", pars[3], step[3], 0,0); | |
74 | ierflg = fitter->SetParameter(4, "theta", pars[4], step[4], 0,0); | |
75 | ierflg = fitter->SetParameter(5, "phi", pars[5], step[5], 0,0); | |
76 | ||
77 | // Fix parameters | |
78 | if(fBFixed[0]) {printf("Fixing dx=%f\n",pars[0]); fitter->FixParameter(0);} | |
79 | if(fBFixed[1]) {printf("Fixing dy=%f\n",pars[1]); fitter->FixParameter(1);} | |
80 | if(fBFixed[2]) {printf("Fixing dz=%f\n",pars[2]); fitter->FixParameter(2);} | |
81 | if(fBFixed[3]) {printf("Fixing psi=%f\n",pars[3]); fitter->FixParameter(3);} | |
82 | if(fBFixed[4]) {printf("Fixing theta=%f\n",pars[4]); fitter->FixParameter(4);} | |
83 | if(fBFixed[5]) {printf("Fixing phi=%f\n",pars[5]); fitter->FixParameter(5);} | |
84 | ||
85 | // Now ready for minimization step | |
86 | arglist[0] = 500; | |
87 | arglist[1] = 1.; | |
88 | fitter->ExecuteCommand("MIGRAD", arglist ,2); | |
89 | ||
90 | // Print results | |
91 | Double_t amin,edm,errdef; | |
92 | Int_t nvpar,nparx,icstat; | |
93 | icstat = fitter->GetStats(amin,edm,errdef,nvpar,nparx); | |
94 | fChi2 = amin; fNdf -= nvpar; | |
95 | ||
96 | return kTRUE; | |
97 | } | |
98 | ||
99 | //______________________________________________________________________________ | |
100 | void AliTrackResidualsChi2::Chi2(Int_t & /* npar */, Double_t * /* gin */, Double_t &f, Double_t *par, Int_t /* iflag */) | |
101 | { | |
102 | // Chi2 function to be minimized | |
103 | // Sums all the track residuals | |
104 | Double_t chi2 = 0; | |
105 | ||
106 | fAlignObj->SetPars(par[0],par[1],par[2],par[3],par[4],par[5]); | |
107 | ||
108 | AliTrackPoint p1,p2; | |
109 | ||
110 | Bool_t count = kFALSE; | |
111 | if (fNdf == 0) count = kTRUE; | |
112 | ||
113 | for (Int_t itrack = 0; itrack < fLast; itrack++) { | |
114 | if (!fVolArray[itrack] || !fTrackArray[itrack]) continue; | |
115 | for (Int_t ipoint = 0; ipoint < fVolArray[itrack]->GetNPoints(); ipoint++) { | |
116 | fVolArray[itrack]->GetPoint(p1,ipoint); | |
117 | fAlignObj->Transform(p1); | |
118 | fTrackArray[itrack]->GetPoint(p2,ipoint); | |
119 | Float_t residual = p2.GetResidual(p1,kTRUE); | |
120 | chi2 += residual; | |
121 | if (count) fNdf += 3; | |
122 | } | |
123 | } | |
124 | f = chi2; | |
125 | } |