TpcDistortionCorrection.cc

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#include "TpcDistortionCorrection.h"
#include "TpcDistortionCorrectionContainer.h"

#include <TH3.h>
#include <cmath>

namespace
{
  template<class T> inline constexpr T square( const T& x ) { return x*x; }
}

//________________________________________________________
Acts::Vector3D TpcDistortionCorrection::get_corrected_position( const Acts::Vector3D& source, const TpcDistortionCorrectionContainer* dcc, unsigned int mask) const
{
  // get cluster radius, phi and z
  const auto r = std::sqrt( square( source.x() ) + square( source.y() ) );
  auto phi = std::atan2( source.y(), source.x() );
  if( phi < 0 ) phi += 2*M_PI;

  const auto z = source.z();
  const int index = z > 0 ? 1:0;

  // apply corrections
  const auto phi_new = (dcc->m_hDPint[index] && (mask&COORD_PHI)) ? phi - dcc->m_hDPint[index]->Interpolate(phi,r,z)/r : phi;
  const auto r_new = (dcc->m_hDRint[index] && (mask&COORD_R)) ? r - dcc->m_hDRint[index]->Interpolate(phi,r,z) : r;
  const auto z_new = (dcc->m_hDZint[index] && (mask&COORD_Z)) ? z - dcc->m_hDZint[index]->Interpolate(phi,r,z) : z;
  
  // update cluster
  const auto x_new = r_new*std::cos( phi_new );
  const auto y_new = r_new*std::sin( phi_new );

  return {x_new, y_new, z_new};
}