// AliTPCExBEffectiveSector class ...

// AliTPCExBEffectiveSector class                                                   //
// Correct for the rest of ExB effect which are not covered yet by physical models
//
// Motivation:
//   ExB correction:
//      dr    =  c0* integral(Er/Ez) + c1* integral(Erphi/Ez)
//      drphi = -c1* integral(Er/Ez) + c0* integral(Erphi/Ez)
//   Where:
//   wt = Bz*(k*vdrift/E)           ~ 0.3 at B=0.5 T
//   c0 = 1/(1+T2*T2*wt*wt)
//   c1 = T1*wt/(1+T1*T1*wt*wt)
//
//
//  3 correction maps 0 implemented as histogram used
//  R-Phi correction map obtained minimizing residuals betwee the track
//        and space points (AliTPCcalibAlign class). Track is defined using
//        the points from the refernce plain at the middle of the TPC
//        and vertex
//        Corrected primar tracks straight pointing to the primary vertex
//
//  R distortion - obtained using the cluster residuals in the setup with
//                 plus and minus field
//                 Only high momenta tracks used for this calibration (1 GeV threshold)
//     drphi_plus-drphi_minus=-2*c1 integral(Er/Ez)
//               - Erphi/Ez cancels

Marian