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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 ITS track class |
| 18 | // |
| 19 | // Origin: Iouri Belikov, CERN, Jouri.Belikov@cern.ch |
| 20 | //------------------------------------------------------------------------- |
| 21 | |
| 22 | #include <TMatrixD.h> |
| 23 | |
| 24 | #include <TMath.h> |
| 25 | #include <iostream.h> |
| 26 | |
| 27 | #include "AliCluster.h" |
| 517b130f |
28 | #include "AliTPCtrack.h" |
| 006b5f7f |
29 | #include "AliITStrackV2.h" |
| 30 | |
| 31 | ClassImp(AliITStrackV2) |
| 32 | |
| 7f6ddf58 |
33 | const Int_t kWARN=5; |
| 006b5f7f |
34 | |
| 35 | //____________________________________________________________________________ |
| 36 | AliITStrackV2::AliITStrackV2(const AliTPCtrack& t) throw (const Char_t *) { |
| 37 | //------------------------------------------------------------------ |
| 9b280d80 |
38 | //Conversion TPC track -> ITS track |
| 006b5f7f |
39 | //------------------------------------------------------------------ |
| 40 | SetLabel(t.GetLabel()); |
| 41 | SetChi2(0.); |
| 42 | SetNumberOfClusters(0); |
| 14825d5a |
43 | //SetConvConst(t.GetConvConst()); |
| 44 | |
| 7f6ddf58 |
45 | fdEdx = t.GetdEdx(); |
| 46 | SetMass(t.GetMass()); |
| 47 | |
| 006b5f7f |
48 | fAlpha = t.GetAlpha(); |
| 49 | if (fAlpha < -TMath::Pi()) fAlpha += 2*TMath::Pi(); |
| 50 | else if (fAlpha >= TMath::Pi()) fAlpha -= 2*TMath::Pi(); |
| 51 | |
| 9b280d80 |
52 | //Conversion of the track parameters |
| 006b5f7f |
53 | Double_t x,p[5]; t.GetExternalParameters(x,p); |
| 9b280d80 |
54 | fX=x; x=GetConvConst(); |
| 006b5f7f |
55 | fP0=p[0]; |
| 56 | fP1=p[1]; |
| 57 | fP2=p[2]; |
| 58 | fP3=p[3]; |
| 59 | fP4=p[4]/x; |
| 60 | |
| 9b280d80 |
61 | //Conversion of the covariance matrix |
| 006b5f7f |
62 | Double_t c[15]; t.GetExternalCovariance(c); |
| 63 | |
| 64 | fC00=c[0 ]; |
| 65 | fC10=c[1 ]; fC11=c[2 ]; |
| 66 | fC20=c[3 ]; fC21=c[4 ]; fC22=c[5 ]; |
| 67 | fC30=c[6 ]; fC31=c[7 ]; fC32=c[8 ]; fC33=c[9 ]; |
| 68 | fC40=c[10]/x; fC41=c[11]/x; fC42=c[12]/x; fC43=c[13]/x; fC44=c[14]/x/x; |
| 69 | |
| 70 | if (!Invariant()) throw "AliITStrackV2: conversion failed !\n"; |
| 71 | } |
| 72 | |
| 73 | //____________________________________________________________________________ |
| 74 | AliITStrackV2::AliITStrackV2(const AliITStrackV2& t) : AliKalmanTrack(t) { |
| 75 | //------------------------------------------------------------------ |
| 76 | //Copy constructor |
| 77 | //------------------------------------------------------------------ |
| 78 | fX=t.fX; |
| 79 | fAlpha=t.fAlpha; |
| 80 | fdEdx=t.fdEdx; |
| 81 | |
| 82 | fP0=t.fP0; fP1=t.fP1; fP2=t.fP2; fP3=t.fP3; fP4=t.fP4; |
| 83 | |
| 84 | fC00=t.fC00; |
| 85 | fC10=t.fC10; fC11=t.fC11; |
| 86 | fC20=t.fC20; fC21=t.fC21; fC22=t.fC22; |
| 87 | fC30=t.fC30; fC31=t.fC31; fC32=t.fC32; fC33=t.fC33; |
| 88 | fC40=t.fC40; fC41=t.fC41; fC42=t.fC42; fC43=t.fC43; fC44=t.fC44; |
| 89 | |
| 90 | Int_t n=GetNumberOfClusters(); |
| 91 | for (Int_t i=0; i<n; i++) fIndex[i]=t.fIndex[i]; |
| 92 | } |
| 7f6ddf58 |
93 | /* |
| 006b5f7f |
94 | //_____________________________________________________________________________ |
| 95 | Int_t AliITStrackV2::Compare(const TObject *o) const { |
| 96 | //----------------------------------------------------------------- |
| 97 | // This function compares tracks according to the their curvature |
| 98 | //----------------------------------------------------------------- |
| 7f6ddf58 |
99 | AliITStrackV2 *t=(AliITStrackV2*)o; |
| 006b5f7f |
100 | Double_t co=TMath::Abs(t->Get1Pt()); |
| 101 | Double_t c =TMath::Abs(Get1Pt()); |
| 102 | if (c>co) return 1; |
| 103 | else if (c<co) return -1; |
| 104 | return 0; |
| 105 | } |
| 7f6ddf58 |
106 | */ |
| 107 | //_____________________________________________________________________________ |
| 108 | Int_t AliITStrackV2::Compare(const TObject *o) const { |
| 109 | //----------------------------------------------------------------- |
| 110 | // This function compares tracks according to the their curvature |
| 111 | //----------------------------------------------------------------- |
| 112 | AliITStrackV2 *t=(AliITStrackV2*)o; |
| 113 | |
| 114 | Double_t p2=1./(Get1Pt()*Get1Pt()); |
| 115 | Double_t b2=p2/(p2 + GetMass()*GetMass()); |
| 116 | Double_t po2=1./(t->Get1Pt()*t->Get1Pt()); |
| 117 | Double_t bo2=po2/(po2 + t->GetMass()*t->GetMass()); |
| 118 | if (p2*b2>po2*bo2) return -1; |
| 119 | else if (p2*b2<po2*bo2) return 1; |
| 120 | return 0; |
| 121 | } |
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122 | |
| 123 | //_____________________________________________________________________________ |
| 124 | void AliITStrackV2::GetExternalCovariance(Double_t cc[15]) const { |
| 125 | //------------------------------------------------------------------------- |
| 126 | // This function returns an external representation of the covriance matrix. |
| 127 | // (See comments in AliTPCtrack.h about external track representation) |
| 128 | //------------------------------------------------------------------------- |
| 9b280d80 |
129 | Double_t a=GetConvConst(); |
| 006b5f7f |
130 | |
| 131 | cc[0 ]=fC00; |
| 132 | cc[1 ]=fC10; cc[2 ]=fC11; |
| 133 | cc[3 ]=fC20; cc[4 ]=fC21; cc[5 ]=fC22; |
| 134 | cc[6 ]=fC30; cc[7 ]=fC31; cc[8 ]=fC32; cc[9 ]=fC33; |
| 135 | cc[10]=fC40*a; cc[11]=fC41*a; cc[12]=fC42*a; cc[13]=fC43*a; cc[14]=fC44*a*a; |
| 136 | } |
| 137 | |
| 138 | //____________________________________________________________________________ |
| 7f6ddf58 |
139 | Int_t AliITStrackV2::PropagateToVertex(Double_t x0,Double_t rho) { |
| 006b5f7f |
140 | //------------------------------------------------------------------ |
| 141 | //This function propagates a track to the minimal distance from the origin |
| 142 | //------------------------------------------------------------------ |
| 143 | Double_t xv=fP2*(fX*fP2 - fP0*TMath::Sqrt(1.- fP2*fP2)); //linear approxim. |
| 7f6ddf58 |
144 | Propagate(fAlpha,xv,0.,0.); |
| 006b5f7f |
145 | return 0; |
| 146 | } |
| 147 | |
| 148 | //____________________________________________________________________________ |
| 149 | Int_t AliITStrackV2:: |
| 150 | GetGlobalXYZat(Double_t xk, Double_t &x, Double_t &y, Double_t &z) const { |
| 151 | //------------------------------------------------------------------ |
| 152 | //This function returns a track position in the global system |
| 153 | //------------------------------------------------------------------ |
| 154 | Double_t dx=xk-fX; |
| 155 | Double_t f1=fP2, f2=f1 + fP4*dx; |
| 156 | if (TMath::Abs(f2) >= 0.99999) { |
| 7f6ddf58 |
157 | Int_t n=GetNumberOfClusters(); |
| 158 | if (n>kWARN) |
| 159 | cerr<<n<<" AliITStrackV2::GetGlobalXYZat: Propagation failed !\n"; |
| 006b5f7f |
160 | return 0; |
| 161 | } |
| 162 | |
| 163 | Double_t r1=sqrt(1.- f1*f1), r2=sqrt(1.- f2*f2); |
| 164 | |
| 165 | Double_t yk = fP0 + dx*(f1+f2)/(r1+r2); |
| 166 | Double_t zk = fP1 + dx*(f1+f2)/(f1*r2 + f2*r1)*fP3; |
| 167 | |
| 168 | Double_t cs=TMath::Cos(fAlpha), sn=TMath::Sin(fAlpha); |
| 169 | x = xk*cs - yk*sn; |
| 170 | y = xk*sn + yk*cs; |
| 171 | z = zk; |
| 172 | |
| 173 | return 1; |
| 174 | } |
| 175 | |
| 176 | //_____________________________________________________________________________ |
| 177 | Double_t AliITStrackV2::GetPredictedChi2(const AliCluster *c) const |
| 178 | { |
| 179 | //----------------------------------------------------------------- |
| 180 | // This function calculates a predicted chi2 increment. |
| 181 | //----------------------------------------------------------------- |
| 182 | Double_t r00=c->GetSigmaY2(), r01=0., r11=c->GetSigmaZ2(); |
| 183 | r00+=fC00; r01+=fC10; r11+=fC11; |
| 184 | |
| 185 | Double_t det=r00*r11 - r01*r01; |
| 7f6ddf58 |
186 | if (TMath::Abs(det) < 1.e-30) { |
| 006b5f7f |
187 | Int_t n=GetNumberOfClusters(); |
| 7f6ddf58 |
188 | if (n>kWARN) |
| 189 | cerr<<n<<" AliKalmanTrack::GetPredictedChi2: Singular matrix !\n"; |
| 006b5f7f |
190 | return 1e10; |
| 191 | } |
| 192 | Double_t tmp=r00; r00=r11; r11=tmp; r01=-r01; |
| 193 | |
| 194 | Double_t dy=c->GetY() - fP0, dz=c->GetZ() - fP1; |
| 195 | |
| 196 | return (dy*r00*dy + 2*r01*dy*dz + dz*r11*dz)/det; |
| 197 | } |
| 198 | |
| 199 | //_____________________________________________________________________________ |
| 200 | Double_t AliITStrackV2::GetPredictedChi2(const AliCluster *c,Double_t *m, |
| 7f6ddf58 |
201 | Double_t x0) const { |
| 006b5f7f |
202 | //----------------------------------------------------------------- |
| 203 | // This function calculates a chi2 increment with a vertex contraint |
| 204 | //----------------------------------------------------------------- |
| 205 | TVectorD x(5); x(0)=fP0; x(1)=fP1; x(2)=fP2; x(3)=fP3; x(4)=fP4; |
| 206 | TMatrixD C(5,5); |
| 207 | C(0,0)=fC00; |
| 208 | C(1,0)=fC10; C(1,1)=fC11; |
| 209 | C(2,0)=fC20; C(2,1)=fC21; C(2,2)=fC22; |
| 210 | C(3,0)=fC30; C(3,1)=fC31; C(3,2)=fC32; C(3,3)=fC33; |
| 211 | C(4,0)=fC40; C(4,1)=fC41; C(4,2)=fC42; C(4,3)=fC43; C(4,4)=fC44; |
| 212 | |
| 213 | C(0,1)=C(1,0); |
| 214 | C(0,2)=C(2,0); C(1,2)=C(2,1); |
| 215 | C(0,3)=C(3,0); C(1,3)=C(3,1); C(2,3)=C(3,2); |
| 216 | C(0,4)=C(4,0); C(1,4)=C(4,1); C(2,4)=C(4,2); C(3,4)=C(4,3); |
| 217 | |
| 218 | TMatrixD H(4,5); H.UnitMatrix(); |
| 219 | Double_t dy=(c->GetY() - m[0]), dz=(c->GetZ() - m[1]); |
| 220 | |
| 221 | Double_t dr=TMath::Sqrt(fX*fX + dy*dy); |
| 222 | Double_t r =TMath::Sqrt(4/dr/dr - fP4*fP4); |
| 223 | Double_t sn=0.5*(fP4*fX + dy*r); |
| 224 | Double_t tg=0.5*fP4*dz/TMath::ASin(0.5*fP4*dr); |
| 225 | TVectorD mm(4); |
| 226 | mm(0)=m[0]=c->GetY(); mm(1)=m[1]=c->GetZ(); mm(2)=m[2]=sn; mm(3)=m[3]=tg; |
| 227 | |
| 228 | Double_t v22=0.,v33=0.; |
| 229 | //x0=0.; |
| 230 | if (x0!=0.) { |
| 231 | Double_t pp2=(1.+ GetTgl()*GetTgl())/(Get1Pt()*Get1Pt()); |
| 7f6ddf58 |
232 | Double_t beta2=pp2/(pp2 + GetMass()*GetMass()); |
| 006b5f7f |
233 | x0*=TMath::Sqrt((1.+ GetTgl()*GetTgl())/(1.- GetSnp()*GetSnp())); |
| 234 | Double_t theta2=14.1*14.1/(beta2*pp2*1e6)*x0; |
| 235 | v22 = theta2*(1.- GetSnp()*GetSnp())*(1. + GetTgl()*GetTgl()); |
| 236 | v33 = theta2*(1.+ GetTgl()*GetTgl())*(1. + GetTgl()*GetTgl()); |
| 237 | } |
| 238 | Double_t sy2=c->GetSigmaY2(), sz2=c->GetSigmaZ2(); |
| 239 | v22+=kSigmaYV*kSigmaYV/dr/dr; |
| 240 | v22+=sy2/dr/dr; |
| 241 | Double_t v20=sy2/dr; |
| 242 | |
| 243 | v33+=kSigmaZV*kSigmaZV/dr/dr; |
| 244 | v33+=sz2/dr/dr; |
| 245 | Double_t v31=sz2/dr; |
| 246 | |
| 247 | TMatrixD V(4,4); |
| 248 | V(0,0)=m[4 ]=sy2; V(0,1)=m[5 ]=0.; V(0,2)=m[6 ]=v20; V(0,3)=m[7 ]=0.; |
| 249 | V(1,0)=m[8 ]=0.; V(1,1)=m[9 ]=sz2; V(1,2)=m[10]=0.; V(1,3)=m[11]=v31; |
| 250 | V(2,0)=m[12]=v20; V(2,1)=m[13]=0.; V(2,2)=m[14]=v22; V(2,3)=m[15]=0.; |
| 251 | V(3,0)=m[16]=0.; V(3,1)=m[17]=v31; V(3,2)=m[18]=0.; V(3,3)=m[19]=v33; |
| 252 | |
| 253 | TVectorD res=x; res*=H; res-=mm; //res*=-1; |
| 254 | TMatrixD tmp(H,TMatrixD::kMult,C); |
| 255 | TMatrixD R(tmp,TMatrixD::kMult,TMatrixD(TMatrixD::kTransposed,H)); R+=V; |
| 256 | |
| 257 | Double_t det=R.Determinant(); |
| 7f6ddf58 |
258 | if (TMath::Abs(det) < 1.e-30) { |
| 006b5f7f |
259 | Int_t n=GetNumberOfClusters(); |
| 7f6ddf58 |
260 | if (n>kWARN) |
| 261 | cerr<<n<<" AliITStrackV2::GetPredictedChi2: Singular matrix !\n"; |
| 006b5f7f |
262 | return 1e10; |
| 263 | } |
| 264 | |
| 265 | R.Invert(); |
| 266 | |
| 267 | TVectorD rs=res; |
| 268 | res*=R; |
| 269 | return rs*res; |
| 270 | } |
| 271 | |
| 272 | //____________________________________________________________________________ |
| 273 | Int_t |
| 7f6ddf58 |
274 | AliITStrackV2::PropagateTo(Double_t xk,Double_t x0,Double_t rho) { |
| 006b5f7f |
275 | //------------------------------------------------------------------ |
| 276 | //This function propagates a track |
| 277 | //------------------------------------------------------------------ |
| 278 | Double_t x1=fX, x2=xk, dx=x2-x1; |
| 279 | Double_t f1=fP2, f2=f1 + fP4*dx; |
| 280 | if (TMath::Abs(f2) >= 0.99999) { |
| 281 | Int_t n=GetNumberOfClusters(); |
| 7f6ddf58 |
282 | if (n>kWARN) |
| 283 | cerr<<n<<" AliITStrackV2::PropagateTo: Propagation failed !\n"; |
| 006b5f7f |
284 | return 0; |
| 285 | } |
| 286 | |
| 287 | Double_t r1=sqrt(1.- f1*f1), r2=sqrt(1.- f2*f2); |
| 288 | |
| 289 | fP0 += dx*(f1+f2)/(r1+r2); |
| 290 | fP1 += dx*(f1+f2)/(f1*r2 + f2*r1)*fP3; |
| 291 | fP2 += dx*fP4; |
| 292 | |
| 293 | //f = F - 1 |
| 294 | |
| 295 | Double_t f02= dx/(r1*r1*r1); |
| 296 | Double_t f04=0.5*dx*dx/(r1*r1*r1); |
| 297 | Double_t f12= dx*fP3*f1/(r1*r1*r1); |
| 298 | Double_t f14=0.5*dx*dx*fP3*f1/(r1*r1*r1); |
| 299 | Double_t f13= dx/r1; |
| 300 | Double_t f24= dx; |
| 301 | |
| 302 | //b = C*ft |
| 303 | Double_t b00=f02*fC20 + f04*fC40, b01=f12*fC20 + f14*fC40 + f13*fC30; |
| 304 | Double_t b02=f24*fC40; |
| 305 | Double_t b10=f02*fC21 + f04*fC41, b11=f12*fC21 + f14*fC41 + f13*fC31; |
| 306 | Double_t b12=f24*fC41; |
| 307 | Double_t b20=f02*fC22 + f04*fC42, b21=f12*fC22 + f14*fC42 + f13*fC32; |
| 308 | Double_t b22=f24*fC42; |
| 309 | Double_t b40=f02*fC42 + f04*fC44, b41=f12*fC42 + f14*fC44 + f13*fC43; |
| 310 | Double_t b42=f24*fC44; |
| 311 | Double_t b30=f02*fC32 + f04*fC43, b31=f12*fC32 + f14*fC43 + f13*fC33; |
| 312 | Double_t b32=f24*fC43; |
| 313 | |
| 314 | //a = f*b = f*C*ft |
| 315 | Double_t a00=f02*b20+f04*b40,a01=f02*b21+f04*b41,a02=f02*b22+f04*b42; |
| 316 | Double_t a11=f12*b21+f14*b41+f13*b31,a12=f12*b22+f14*b42+f13*b32; |
| 317 | Double_t a22=f24*b42; |
| 318 | |
| 319 | //F*C*Ft = C + (b + bt + a) |
| 320 | fC00 += b00 + b00 + a00; |
| 321 | fC10 += b10 + b01 + a01; |
| 322 | fC20 += b20 + b02 + a02; |
| 323 | fC30 += b30; |
| 324 | fC40 += b40; |
| 325 | fC11 += b11 + b11 + a11; |
| 326 | fC21 += b21 + b12 + a12; |
| 327 | fC31 += b31; |
| 328 | fC41 += b41; |
| 329 | fC22 += b22 + b22 + a22; |
| 330 | fC32 += b32; |
| 331 | fC42 += b42; |
| 332 | |
| 333 | fX=x2; |
| 334 | |
| 335 | Double_t p2=(1.+ GetTgl()*GetTgl())/(Get1Pt()*Get1Pt()); |
| 7f6ddf58 |
336 | Double_t beta2=p2/(p2 + GetMass()*GetMass()); |
| 006b5f7f |
337 | |
| 338 | //Multiple scattering****************** |
| 339 | //x0=0.; |
| 340 | if (x0!=0) { |
| 341 | x0*=TMath::Sqrt((1.+ fP3*fP3)/(1.- fP2*fP2)); |
| 342 | Double_t theta2=14.1*14.1/(beta2*p2*1e6)*x0; |
| 343 | fC22 += theta2*(1.- fP2*fP2)*(1. + fP3*fP3); |
| 344 | fC33 += theta2*(1. + fP3*fP3)*(1. + fP3*fP3); |
| 345 | fC43 += theta2*fP3*fP4*(1. + fP3*fP3); |
| 346 | fC44 += theta2*fP3*fP4*fP3*fP4; |
| 347 | } |
| 348 | |
| 349 | //Energy losses************************ |
| 350 | if (rho!=0.) { |
| 351 | rho*=TMath::Sqrt((1.+ fP3*fP3)/(1.- fP2*fP2)); |
| 352 | Double_t dE=0.153e-3/beta2*(log(5940*beta2/(1-beta2)) - beta2)*rho; |
| 353 | if (x1 < x2) dE=-dE; |
| 7f6ddf58 |
354 | fP4*=(1.- sqrt(p2+GetMass()*GetMass())/p2*dE); |
| 006b5f7f |
355 | } |
| 356 | |
| 357 | if (!Invariant()) {cout<<"Propagate !\n"; return 0;} |
| 358 | |
| 359 | return 1; |
| 360 | } |
| 361 | |
| 362 | //____________________________________________________________________________ |
| 363 | Int_t AliITStrackV2::Update(const AliCluster* c, Double_t chi2, UInt_t index) { |
| 364 | //------------------------------------------------------------------ |
| 365 | //This function updates track parameters |
| 366 | //------------------------------------------------------------------ |
| 367 | Double_t p0=fP0,p1=fP1,p2=fP2,p3=fP3,p4=fP4; |
| 368 | Double_t c00=fC00; |
| 369 | Double_t c10=fC10, c11=fC11; |
| 370 | Double_t c20=fC20, c21=fC21, c22=fC22; |
| 371 | Double_t c30=fC30, c31=fC31, c32=fC32, c33=fC33; |
| 372 | Double_t c40=fC40, c41=fC41, c42=fC42, c43=fC43, c44=fC44; |
| 373 | |
| 374 | |
| 375 | Double_t r00=c->GetSigmaY2(), r01=0., r11=c->GetSigmaZ2(); |
| 376 | r00+=fC00; r01+=fC10; r11+=fC11; |
| 377 | Double_t det=r00*r11 - r01*r01; |
| 378 | Double_t tmp=r00; r00=r11/det; r11=tmp/det; r01=-r01/det; |
| 379 | |
| 380 | Double_t k00=fC00*r00+fC10*r01, k01=fC00*r01+fC10*r11; |
| 381 | Double_t k10=fC10*r00+fC11*r01, k11=fC10*r01+fC11*r11; |
| 382 | Double_t k20=fC20*r00+fC21*r01, k21=fC20*r01+fC21*r11; |
| 383 | Double_t k30=fC30*r00+fC31*r01, k31=fC30*r01+fC31*r11; |
| 384 | Double_t k40=fC40*r00+fC41*r01, k41=fC40*r01+fC41*r11; |
| 385 | |
| 386 | Double_t dy=c->GetY() - fP0, dz=c->GetZ() - fP1; |
| 387 | Double_t sf=fP2 + k20*dy + k21*dz; |
| 7f6ddf58 |
388 | |
| 006b5f7f |
389 | fP0 += k00*dy + k01*dz; |
| 390 | fP1 += k10*dy + k11*dz; |
| 391 | fP2 = sf; |
| 392 | fP3 += k30*dy + k31*dz; |
| 393 | fP4 += k40*dy + k41*dz; |
| 394 | |
| 395 | Double_t c01=fC10, c02=fC20, c03=fC30, c04=fC40; |
| 396 | Double_t c12=fC21, c13=fC31, c14=fC41; |
| 397 | |
| 398 | fC00-=k00*fC00+k01*fC10; fC10-=k00*c01+k01*fC11; |
| 399 | fC20-=k00*c02+k01*c12; fC30-=k00*c03+k01*c13; |
| 400 | fC40-=k00*c04+k01*c14; |
| 401 | |
| 402 | fC11-=k10*c01+k11*fC11; |
| 403 | fC21-=k10*c02+k11*c12; fC31-=k10*c03+k11*c13; |
| 404 | fC41-=k10*c04+k11*c14; |
| 405 | |
| 406 | fC22-=k20*c02+k21*c12; fC32-=k20*c03+k21*c13; |
| 407 | fC42-=k20*c04+k21*c14; |
| 408 | |
| 409 | fC33-=k30*c03+k31*c13; |
| 410 | fC43-=k30*c04+k31*c14; |
| 411 | |
| 412 | fC44-=k40*c04+k41*c14; |
| 413 | |
| 414 | if (!Invariant()) { |
| 415 | fP0=p0; fP1=p1; fP2=p2; fP3=p3; fP4=p4; |
| 416 | fC00=c00; |
| 417 | fC10=c10; fC11=c11; |
| 418 | fC20=c20; fC21=c21; fC22=c22; |
| 419 | fC30=c30; fC31=c31; fC32=c32; fC33=c33; |
| 420 | fC40=c40; fC41=c41; fC42=c42; fC43=c43; fC44=c44; |
| 421 | return 0; |
| 422 | } |
| 423 | |
| 424 | Int_t n=GetNumberOfClusters(); |
| 425 | fIndex[n]=index; |
| 426 | SetNumberOfClusters(n+1); |
| 427 | SetChi2(GetChi2()+chi2); |
| 428 | |
| 429 | return 1; |
| 430 | } |
| 431 | |
| 432 | |
| 433 | //____________________________________________________________________________ |
| 434 | Int_t AliITStrackV2::Update(const Double_t* m, Double_t chi2, UInt_t index) { |
| 435 | //------------------------------------------------------------------ |
| 436 | //This function updates track parameters with a vertex constraint |
| 437 | //------------------------------------------------------------------ |
| 438 | Double_t p0=fP0,p1=fP1,p2=fP2,p3=fP3,p4=fP4; |
| 439 | Double_t c00=fC00; |
| 440 | Double_t c10=fC10, c11=fC11; |
| 441 | Double_t c20=fC20, c21=fC21, c22=fC22; |
| 442 | Double_t c30=fC30, c31=fC31, c32=fC32, c33=fC33; |
| 443 | Double_t c40=fC40, c41=fC41, c42=fC42, c43=fC43, c44=fC44; |
| 444 | |
| 445 | |
| 446 | TVectorD x(5); x(0)=fP0; x(1)=fP1; x(2)=fP2; x(3)=fP3; x(4)=fP4; |
| 447 | TMatrixD C(5,5); |
| 448 | C(0,0)=fC00; |
| 449 | C(1,0)=fC10; C(1,1)=fC11; |
| 450 | C(2,0)=fC20; C(2,1)=fC21; C(2,2)=fC22; |
| 451 | C(3,0)=fC30; C(3,1)=fC31; C(3,2)=fC32; C(3,3)=fC33; |
| 452 | C(4,0)=fC40; C(4,1)=fC41; C(4,2)=fC42; C(4,3)=fC43; C(4,4)=fC44; |
| 453 | |
| 454 | C(0,1)=C(1,0); |
| 455 | C(0,2)=C(2,0); C(1,2)=C(2,1); |
| 456 | C(0,3)=C(3,0); C(1,3)=C(3,1); C(2,3)=C(3,2); |
| 457 | C(0,4)=C(4,0); C(1,4)=C(4,1); C(2,4)=C(4,2); C(3,4)=C(4,3); |
| 458 | |
| 459 | TMatrixD H(4,5); H.UnitMatrix(); |
| 460 | TMatrixD Ht(TMatrixD::kTransposed,H); |
| 461 | TVectorD mm(4); mm(0)=m[0]; mm(1)=m[1]; mm(2)=m[2]; mm(3)=m[3]; |
| 462 | TMatrixD V(4,4); |
| 463 | V(0,0)=m[4 ]; V(0,1)=m[5 ]; V(0,2)=m[6 ]; V(0,3)=m[7 ]; |
| 464 | V(1,0)=m[8 ]; V(1,1)=m[9 ]; V(1,2)=m[10]; V(1,3)=m[11]; |
| 465 | V(2,0)=m[12]; V(2,1)=m[13]; V(2,2)=m[14]; V(2,3)=m[15]; |
| 466 | V(3,0)=m[16]; V(3,1)=m[17]; V(3,2)=m[18]; V(3,3)=m[19]; |
| 467 | |
| 468 | TMatrixD tmp(H,TMatrixD::kMult,C); |
| 469 | TMatrixD R(tmp,TMatrixD::kMult,Ht); R+=V; |
| 470 | |
| 471 | R.Invert(); |
| 472 | |
| 473 | TMatrixD K(C,TMatrixD::kMult,Ht); K*=R; |
| 474 | |
| 475 | TVectorD savex=x; |
| 476 | x*=H; x-=mm; x*=-1; x*=K; x+=savex; |
| 477 | |
| 478 | TMatrixD saveC=C; |
| 479 | C.Mult(K,tmp); C-=saveC; C*=-1; |
| 480 | |
| 481 | fP0=x(0); fP1=x(1); fP2=x(2); fP3=x(3); fP4=x(4); |
| 482 | fC00=C(0,0); |
| 483 | fC10=C(1,0); fC11=C(1,1); |
| 484 | fC20=C(2,0); fC21=C(2,1); fC22=C(2,2); |
| 485 | fC30=C(3,0); fC31=C(3,1); fC32=C(3,2); fC33=C(3,3); |
| 486 | fC40=C(4,0); fC41=C(4,1); fC42=C(4,2); fC43=C(4,3); fC44=C(4,4); |
| 487 | |
| 488 | |
| 489 | if (!Invariant()) { |
| 490 | fP0=p0; fP1=p1; fP2=p2; fP3=p3; fP4=p4; |
| 491 | fC00=c00; |
| 492 | fC10=c10; fC11=c11; |
| 493 | fC20=c20; fC21=c21; fC22=c22; |
| 494 | fC30=c30; fC31=c31; fC32=c32; fC33=c33; |
| 495 | fC40=c40; fC41=c41; fC42=c42; fC43=c43; fC44=c44; |
| 496 | return 0; |
| 497 | } |
| 498 | |
| 499 | Int_t n=GetNumberOfClusters(); |
| 500 | fIndex[n]=index; |
| 501 | SetNumberOfClusters(n+1); |
| 502 | SetChi2(GetChi2()+chi2); |
| 503 | |
| 504 | return 1; |
| 505 | } |
| 506 | |
| 507 | Int_t AliITStrackV2::Invariant() const { |
| 508 | //------------------------------------------------------------------ |
| 509 | // This function is for debugging purpose only |
| 510 | //------------------------------------------------------------------ |
| 7f6ddf58 |
511 | Int_t n=GetNumberOfClusters(); |
| 512 | |
| 006b5f7f |
513 | //if (TMath::Abs(fP1)>11.5) |
| 7f6ddf58 |
514 | //if (fP1*fP4<0) { |
| 515 | // if (n>kWARN) cout<<"fP1*fP4="<<fP1*fP4<<' '<<fP1<<endl; return 0;} |
| 516 | |
| 517 | if (TMath::Abs(fP2)>=1) {if (n>kWARN) cout<<"fP2="<<fP2<<endl; return 0;} |
| 518 | |
| 519 | if (fC00<=0) {if (n>kWARN) cout<<"fC00="<<fC00<<endl; return 0;} |
| 520 | if (fC11<=0) {if (n>kWARN) cout<<"fC11="<<fC11<<endl; return 0;} |
| 521 | if (fC22<=0) {if (n>kWARN) cout<<"fC22="<<fC22<<endl; return 0;} |
| 522 | if (fC33<=0) {if (n>kWARN) cout<<"fC33="<<fC33<<endl; return 0;} |
| 523 | if (fC44<=0) {if (n>kWARN) cout<<"fC44="<<fC44<<endl; return 0;} |
| 14825d5a |
524 | /* |
| 525 | TMatrixD m(5,5); |
| 526 | m(0,0)=fC00; |
| 527 | m(1,0)=fC10; m(1,1)=fC11; |
| 528 | m(2,0)=fC20; m(2,1)=fC21; m(2,2)=fC22; |
| 529 | m(3,0)=fC30; m(3,1)=fC31; m(3,2)=fC32; m(3,3)=fC33; |
| 530 | m(4,0)=fC40; m(4,1)=fC41; m(4,2)=fC42; m(4,3)=fC43; m(4,4)=fC44; |
| 531 | |
| 532 | m(0,1)=m(1,0); |
| 533 | m(0,2)=m(2,0); m(1,2)=m(2,1); |
| 534 | m(0,3)=m(3,0); m(1,3)=m(3,1); m(2,3)=m(3,2); |
| 535 | m(0,4)=m(4,0); m(1,4)=m(4,1); m(2,4)=m(4,2); m(3,4)=m(4,3); |
| 536 | |
| 537 | Double_t det=m.Determinant(); |
| 538 | |
| 539 | if (det <= 0) { |
| 7f6ddf58 |
540 | if (n>kWARN) { cout<<" bad determinant "<<det<<endl; m.Print(); } |
| 14825d5a |
541 | return 0; |
| 542 | } |
| 543 | */ |
| 544 | return 1; |
| 006b5f7f |
545 | } |
| 546 | |
| 547 | //____________________________________________________________________________ |
| 7f6ddf58 |
548 | Int_t |
| 549 | AliITStrackV2::Propagate(Double_t alp,Double_t xk,Double_t x0,Double_t rho) { |
| 006b5f7f |
550 | //------------------------------------------------------------------ |
| 551 | //This function propagates a track |
| 552 | //------------------------------------------------------------------ |
| 553 | Double_t p0=fP0,p1=fP1,p2=fP2,p3=fP3,p4=fP4; |
| 554 | Double_t c00=fC00; |
| 555 | Double_t c10=fC10, c11=fC11; |
| 556 | Double_t c20=fC20, c21=fC21, c22=fC22; |
| 557 | Double_t c30=fC30, c31=fC31, c32=fC32, c33=fC33; |
| 558 | Double_t c40=fC40, c41=fC41, c42=fC42, c43=fC43, c44=fC44; |
| 559 | |
| 560 | |
| 561 | Double_t dalp=alp-fAlpha; |
| 562 | |
| 563 | Double_t ca=TMath::Cos(dalp), sa=TMath::Sin(dalp); |
| 564 | Double_t sf=fP2, cf=TMath::Sqrt(1.- fP2*fP2); |
| 565 | |
| 566 | Double_t pp2=fP2*ca - cf*sa; |
| 567 | if (TMath::Abs(pp2) >= 0.99999) { |
| 568 | Int_t n=GetNumberOfClusters(); |
| 7f6ddf58 |
569 | if (n>kWARN) |
| 570 | cerr<<n<<" AliITStrackV2::Propagate: Rotation failed !\n"; |
| 006b5f7f |
571 | return 0; |
| 572 | } |
| 573 | |
| 574 | fAlpha = alp; |
| 575 | if (fAlpha < -TMath::Pi()) fAlpha += 2*TMath::Pi(); |
| 576 | else if (fAlpha >= TMath::Pi()) fAlpha -= 2*TMath::Pi(); |
| 577 | |
| 578 | Double_t x1=fX, y1=fP0; |
| 579 | |
| 580 | fX = x1*ca + y1*sa; |
| 581 | fP0=-x1*sa + y1*ca; |
| 582 | fP2 = pp2; |
| 583 | |
| 584 | cf=ca + sf*sa/cf; |
| 585 | |
| 586 | if (!Invariant()) {cout<<dalp<<" Rotate !\n"; return 0;} |
| 587 | |
| 588 | x1=fX; Double_t x2=xk, dx=x2-x1; |
| 589 | Double_t f1=fP2, f2=f1 + fP4*dx; |
| 590 | if (TMath::Abs(f2) >= 0.99999) { |
| 591 | Int_t n=GetNumberOfClusters(); |
| 7f6ddf58 |
592 | if (n>kWARN) |
| 593 | cerr<<n<<" AliITStrackV2::Propagate: Propagation failed !\n"; |
| 006b5f7f |
594 | return 0; |
| 595 | } |
| 596 | |
| 597 | Double_t r1=sqrt(1.- f1*f1), r2=sqrt(1.- f2*f2); |
| 598 | |
| 599 | fP0 += dx*(f1+f2)/(r1+r2); |
| 600 | fP1 += dx*(f1+f2)/(f1*r2 + f2*r1)*fP3; |
| 601 | fP2 += dx*fP4; |
| 602 | |
| 603 | //f = F - 1 |
| 604 | Double_t f02= dx/(r1*r1*r1); |
| 605 | Double_t f04=0.5*dx*dx/(r1*r1*r1); |
| 606 | Double_t f12= dx*fP3*f1/(r1*r1*r1); |
| 607 | Double_t f14=0.5*dx*dx*fP3*f1/(r1*r1*r1); |
| 608 | Double_t f13= dx/r1; |
| 609 | Double_t f24= dx; |
| 610 | /* |
| 611 | //b = C*ft |
| 612 | Double_t b00=f02*fC20 + f03*fC30, b01=f12*fC20 + f13*fC30 + f14*fC40; |
| 613 | Double_t b02=f23*fC30; |
| 614 | Double_t b10=f02*fC21 + f03*fC31, b11=f12*fC21 + f13*fC31 + f14*fC41; |
| 615 | Double_t b12=f23*fC31; |
| 616 | Double_t b20=f02*fC22 + f03*fC32, b21=f12*fC22 + f13*fC32 + f14*fC42; |
| 617 | Double_t b22=f23*fC32; |
| 618 | Double_t b30=f02*fC32 + f03*fC33, b31=f12*fC32 + f13*fC33 + f14*fC43; |
| 619 | Double_t b32=f23*fC33; |
| 620 | Double_t b40=f02*fC42 + f03*fC43, b41=f12*fC42 + f13*fC43 + f14*fC44; |
| 621 | Double_t b42=f23*fC43; |
| 622 | |
| 623 | //a = f*b = f*C*ft |
| 624 | Double_t a00=f02*b20+f03*b30,a01=f02*b21+f03*b31,a02=f02*b22+f03*b32; |
| 625 | Double_t a11=f12*b21+f13*b31+f14*b41,a12=f12*b22+f13*b32+f14*b42; |
| 626 | Double_t a22=f23*b32; |
| 627 | |
| 628 | //F*C*Ft = C + (b + bt + a) |
| 629 | fC00 += b00 + b00 + a00; |
| 630 | fC10 += b10 + b01 + a01; |
| 631 | fC20 += b20 + b02 + a02; |
| 632 | fC30 += b30; |
| 633 | fC40 += b40; |
| 634 | fC11 += b11 + b11 + a11; |
| 635 | fC21 += b21 + b12 + a12; |
| 636 | fC31 += b31; |
| 637 | fC41 += b41; |
| 638 | fC22 += b22 + b22 + a22; |
| 639 | fC32 += b32; |
| 640 | fC42 += b42; |
| 641 | */ |
| 642 | |
| 643 | TMatrixD F(5,5); F.UnitMatrix(); |
| 644 | F(0,0)=-(f1+f2)/(r1+r2)*sa + ca; F(0,2)=f02*cf; F(0,4)=f04; |
| 645 | F(1,0)=-(f1+f2)/(f1*r2 + f2*r1)*fP3*sa; F(1,2)=f12*cf; F(1,4)=f14; F(1,3)=f13; |
| 646 | F(2,0)=-fP4*sa; F(2,2)=cf; F(2,4)=f24; |
| 647 | |
| 648 | TMatrixD C(5,5); |
| 649 | C(0,0)=fC00; |
| 650 | C(1,0)=fC10; C(1,1)=fC11; |
| 651 | C(2,0)=fC20; C(2,1)=fC21; C(2,2)=fC22; |
| 652 | C(3,0)=fC30; C(3,1)=fC31; C(3,2)=fC32; C(3,3)=fC33; |
| 653 | C(4,0)=fC40; C(4,1)=fC41; C(4,2)=fC42; C(4,3)=fC43; C(4,4)=fC44; |
| 654 | |
| 655 | C(0,1)=C(1,0); |
| 656 | C(0,2)=C(2,0); C(1,2)=C(2,1); |
| 657 | C(0,3)=C(3,0); C(1,3)=C(3,1); C(2,3)=C(3,2); |
| 658 | C(0,4)=C(4,0); C(1,4)=C(4,1); C(2,4)=C(4,2); C(3,4)=C(4,3); |
| 659 | |
| 660 | TMatrixD tmp(C,TMatrixD::kMult,TMatrixD(TMatrixD::kTransposed, F)); |
| 661 | C.Mult(F,tmp); |
| 662 | |
| 663 | fC00=C(0,0); |
| 664 | fC10=C(1,0); fC11=C(1,1); |
| 665 | fC20=C(2,0); fC21=C(2,1); fC22=C(2,2); |
| 666 | fC30=C(3,0); fC31=C(3,1); fC32=C(3,2); fC33=C(3,3); |
| 667 | fC40=C(4,0); fC41=C(4,1); fC42=C(4,2); fC43=C(4,3); fC44=C(4,4); |
| 668 | |
| 669 | pp2=(1.+ GetTgl()*GetTgl())/(Get1Pt()*Get1Pt()); |
| 7f6ddf58 |
670 | Double_t beta2=pp2/(pp2 + GetMass()*GetMass()); |
| 006b5f7f |
671 | |
| 672 | //Multiple scattering****************** |
| 673 | //x0=0.; |
| 674 | if (x0!=0.) { |
| 675 | x0*=TMath::Sqrt((1.+ fP3*fP3)/(1.- fP2*fP2)); |
| 676 | Double_t theta2=14.1*14.1/(beta2*pp2*1e6)*x0; |
| 677 | fC22 += theta2*(1.- fP2*fP2)*(1. + fP3*fP3); |
| 678 | fC33 += theta2*(1. + fP3*fP3)*(1. + fP3*fP3); |
| 679 | fC43 += theta2*fP3*fP4*(1. + fP3*fP3); |
| 680 | fC44 += theta2*fP3*fP4*fP3*fP4; |
| 681 | } |
| 682 | |
| 683 | //Energy losses************************ |
| 684 | if (rho!=0.) { |
| 685 | rho*=TMath::Sqrt((1.+ fP3*fP3)/(1.- fP2*fP2)); |
| 686 | Double_t dE=0.153e-3/beta2*(log(5940*beta2/(1-beta2)) - beta2)*rho; |
| 687 | if (x1 < x2) dE=-dE; |
| 7f6ddf58 |
688 | fP4*=(1.- sqrt(pp2+GetMass()*GetMass())/pp2*dE); |
| 006b5f7f |
689 | } |
| 690 | |
| 691 | if (!Invariant()) { |
| 692 | fP0=p0; fP1=p1; fP2=p2; fP3=p3; fP4=p4; |
| 693 | fC00=c00; |
| 694 | fC10=c10; fC11=c11; |
| 695 | fC20=c20; fC21=c21; fC22=c22; |
| 696 | fC30=c30; fC31=c31; fC32=c32; fC33=c33; |
| 697 | fC40=c40; fC41=c41; fC42=c42; fC43=c43; fC44=c44; |
| 698 | return 0; |
| 699 | } |
| 700 | |
| 701 | fX=x2; |
| 702 | |
| 703 | return 1; |
| 704 | } |
| 705 | |
| 706 | Double_t AliITStrackV2::GetD() const { |
| 707 | //------------------------------------------------------------------ |
| 708 | //This function calculates the transverse impact parameter |
| 709 | //------------------------------------------------------------------ |
| 710 | Double_t sn=fP4*fX - fP2, cs=fP4*fP0 + TMath::Sqrt(1.- fP2*fP2); |
| 711 | Double_t a=2*(fX*fP2 - fP0*TMath::Sqrt(1.- fP2*fP2))-fP4*(fX*fX + fP0*fP0); |
| 712 | if (fP4<0) a=-a; |
| 713 | return a/(1 + TMath::Sqrt(sn*sn + cs*cs)); |
| 714 | } |
| 715 | |
| 716 | |
| 717 | Int_t AliITStrackV2::Improve(Double_t x0,Double_t yv,Double_t zv) { |
| 718 | //------------------------------------------------------------------ |
| 719 | //This function improves angular track parameters |
| 720 | //------------------------------------------------------------------ |
| 721 | Double_t dy=fP0-yv, dz=fP1-zv; |
| 722 | Double_t r2=fX*fX+dy*dy; |
| 723 | Double_t p2=(1.+ GetTgl()*GetTgl())/(Get1Pt()*Get1Pt()); |
| 7f6ddf58 |
724 | Double_t beta2=p2/(p2 + GetMass()*GetMass()); |
| 006b5f7f |
725 | x0*=TMath::Sqrt((1.+ GetTgl()*GetTgl())/(1.- GetSnp()*GetSnp())); |
| 726 | Double_t theta2=14.1*14.1/(beta2*p2*1e6)*x0; |
| 727 | |
| 728 | Double_t par=0.5*(fP4*fX + dy*TMath::Sqrt(4/r2-fP4*fP4)); |
| 729 | Double_t sigma2 = theta2*(1.- GetSnp()*GetSnp())*(1. + GetTgl()*GetTgl()); |
| 730 | sigma2 += fC00/r2*(1.- dy*dy/r2)*(1.- dy*dy/r2); |
| 731 | sigma2 += kSigmaYV*kSigmaYV/r2; |
| 732 | sigma2 += 0.25*fC44*fX*fX; |
| 733 | Double_t eps2=sigma2/(fC22+sigma2), eps=TMath::Sqrt(eps2); |
| 734 | if (10*r2*fC44<fC22) { |
| 735 | fP2 = eps2*fP2 + (1-eps2)*par; |
| 736 | fC22*=eps2; fC21*=eps; fC20*=eps; fC32*=eps; fC42*=eps; |
| 737 | } |
| 738 | |
| 739 | par=0.5*fP4*dz/TMath::ASin(0.5*fP4*TMath::Sqrt(r2)); |
| 740 | sigma2=theta2; |
| 741 | sigma2 += fC11/r2+fC00*dy*dy*dz*dz/(r2*r2*r2); |
| 742 | sigma2 += kSigmaZV*kSigmaZV/r2; |
| 743 | eps2=sigma2/(fC33+sigma2); eps=TMath::Sqrt(eps2); |
| 744 | Double_t tgl=fP3; |
| 745 | fP3 = eps2*fP3 + (1-eps2)*par; |
| 746 | fC33*=eps2; fC32*=eps; fC31*=eps; fC30*=eps; fC43*=eps; |
| 747 | |
| 748 | eps=TMath::Sqrt((1+fP3*fP3)/(1+tgl*tgl)); |
| 749 | fP4*=eps; |
| 750 | fC44*=eps*eps; fC43*=eps;fC42*=eps; fC41*=eps; fC40*=eps; |
| 751 | |
| 752 | if (!Invariant()) return 0; |
| 753 | return 1; |
| 754 | } |
| 755 | |
| 756 | /* |
| 757 | Int_t AliITStrackV2::Improve(Double_t x0,Double_t xv,Double_t yv) { |
| 758 | //------------------------------------------------------------------ |
| 759 | //This function improves angular track parameters |
| 760 | //------------------------------------------------------------------ |
| 761 | TMatrixD I(5,5); |
| 762 | TVectorD v(5); v(0)=fP0; v(1)=fP1; v(2)=fP2; v(3)=fP3; v(4)=fP4; |
| 763 | |
| 764 | Double_t r2=fX*fX+fP0*fP0; |
| 765 | Double_t p2=(1.+ GetTgl()*GetTgl())/(Get1Pt()*Get1Pt()); |
| 7f6ddf58 |
766 | Double_t beta2=p2/(p2 + GetMass()*GetMass()); |
| 006b5f7f |
767 | x0*=TMath::Sqrt((1.+ GetTgl()*GetTgl())/(1.- GetSnp()*GetSnp())); |
| 768 | Double_t theta2=14.1*14.1/(beta2*p2*1e6)*x0; |
| 769 | |
| 770 | v(2)=0.5*(fP4*fX + fP0*TMath::Sqrt(4/r2-fP4*fP4)); |
| 771 | Double_t sigma2 = theta2*(1.- GetSnp()*GetSnp())*(1. + GetTgl()*GetTgl()); |
| 772 | sigma2 += fC00/r2*(1.- fP0*fP0/r2)*(1.- fP0*fP0/r2); |
| 773 | sigma2 += kSigmaYV*kSigmaYV/r2; |
| 774 | I(2,2)=1/sigma2; |
| 775 | |
| 776 | v(3)=0.5*fP4*fP1/TMath::ASin(0.5*fP4*TMath::Sqrt(r2)); |
| 777 | sigma2=theta2; |
| 778 | sigma2 += fC11/r2+fC00*fP0*fP0*fP1*fP1/(r2*r2*r2); |
| 779 | sigma2 += kSigmaZV*kSigmaZV/r2; |
| 780 | I(3,3)=1/sigma2; |
| 781 | |
| 782 | Double_t tgl=fP3; |
| 783 | |
| 784 | TVectorD x(5); x(0)=fP0; x(1)=fP1; x(2)=fP2; x(3)=fP3; x(4)=fP4; |
| 785 | TMatrixD C(5,5); |
| 786 | C(0,0)=fC00; |
| 787 | C(1,0)=fC10; C(1,1)=fC11; |
| 788 | C(2,0)=fC20; C(2,1)=fC21; C(2,2)=fC22; |
| 789 | C(3,0)=fC30; C(3,1)=fC31; C(3,2)=fC32; C(3,3)=fC33; |
| 790 | C(4,0)=fC40; C(4,1)=fC41; C(4,2)=fC42; C(4,3)=fC43; C(4,4)=fC44; |
| 791 | |
| 792 | C(0,1)=C(1,0); |
| 793 | C(0,2)=C(2,0); C(1,2)=C(2,1); |
| 794 | C(0,3)=C(3,0); C(1,3)=C(3,1); C(2,3)=C(3,2); |
| 795 | C(0,4)=C(4,0); C(1,4)=C(4,1); C(2,4)=C(4,2); C(3,4)=C(4,3); |
| 796 | |
| 797 | TMatrixD tmp(I,TMatrixD::kMult,C),U(5,5); U.UnitMatrix(); |
| 798 | U+=tmp; |
| 799 | U.Invert(); |
| 800 | TMatrixD W1(U); |
| 801 | TMatrixD W2(tmp,TMatrixD::kMult,W1); |
| 802 | |
| 803 | v*=W2; x*=W1; x+=v; |
| 804 | |
| 805 | C*=W1; |
| 806 | |
| 807 | |
| 808 | fP0=x(0); fP1=x(1); fP2=x(2); fP3=x(3); fP4=x(4); |
| 809 | fC00=C(0,0); |
| 810 | fC10=C(1,0); fC11=C(1,1); |
| 811 | fC20=C(2,0); fC21=C(2,1); fC22=C(2,2); |
| 812 | fC30=C(3,0); fC31=C(3,1); fC32=C(3,2); fC33=C(3,3); |
| 813 | fC40=C(4,0); fC41=C(4,1); fC42=C(4,2); fC43=C(4,3); fC44=C(4,4); |
| 814 | |
| 815 | eps=TMath::Sqrt((1+fP3*fP3)/(1+tgl*tgl)); |
| 816 | fP4*=eps; |
| 817 | fC44*=eps*eps; fC43*=eps;fC42*=eps; fC41*=eps; fC40*=eps; |
| 818 | |
| 819 | if (!Invariant()) return 0; |
| 820 | return 1; |
| 821 | } |
| 822 | */ |
| 823 | |
| 14825d5a |
824 | void AliITStrackV2::ResetCovariance() { |
| 825 | //------------------------------------------------------------------ |
| 826 | //This function makes a track forget its history :) |
| 827 | //------------------------------------------------------------------ |
| 828 | |
| 829 | fC00*=10.; |
| 830 | fC10=0.; fC11*=10.; |
| 831 | fC20=0.; fC21=0.; fC22*=10.; |
| 832 | fC30=0.; fC31=0.; fC32=0.; fC33*=10.; |
| 833 | fC40=0.; fC41=0.; fC42=0.; fC43=0.; fC44*=10.; |
| 834 | |
| 835 | } |
git://git.uio.no / u / mrichter / AliRoot.git / blame