GenericMinL3Algorithm.cc

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#include "Calibration/Tools/interface/GenericMinL3Algorithm.h"

GenericMinL3Algorithm::GenericMinL3Algorithm(bool normalise)
    : normaliseFlag(normalise)
// if normalize=true: for all events sum the e25ovTRP. then take the mean value and rescale all TrP
{}

GenericMinL3Algorithm::~GenericMinL3Algorithm() {}

std::vector<float> GenericMinL3Algorithm::iterate(const std::vector<std::vector<float> >& eventMatrix,
                                                  const std::vector<float>& energyVector,
                                                  const int nIter) {
  std::vector<float> solution;
  std::vector<std::vector<float> > myEventMatrix(eventMatrix);
  int Nevents = eventMatrix.size();       // Number of events to calibrate with
  int Nchannels = eventMatrix[0].size();  // Number of channel coefficients
  std::vector<float> theCalibVector(Nchannels, 1.);

  // Iterate the correction
  for (int iter = 1; iter <= nIter; iter++) {
    // make one iteration
    solution = iterate(myEventMatrix, energyVector);

    if (solution.empty())
      return solution;
    // R.O.: or throw an exception, what's the standard CMS way ?

    // re-calibrate eventMatrix with solution
    for (int i = 0; i < Nchannels; i++) {
      for (int ievent = 0; ievent < Nevents; ievent++) {
        myEventMatrix[ievent][i] *= solution[i];
      }
      // save solution into theCalibVector
      theCalibVector[i] *= solution[i];
    }

  }  // end iterate the correction

  return theCalibVector;
}

std::vector<float> GenericMinL3Algorithm::iterate(const std::vector<std::vector<float> >& eventMatrix,
                                                  const std::vector<float>& energyVector) {
  std::vector<float> solution;
  std::vector<float> myEnergyVector(energyVector);

  int Nevents = eventMatrix.size();       // Number of events to calibrate with
  int Nchannels = eventMatrix[0].size();  // Number of channel coefficients

  // Sanity check
  if (Nevents != int(myEnergyVector.size())) {
    std::cout << "GenericMinL3Algorithm::iterate(): Error: bad matrix dimensions. Dropping out." << std::endl;
    return solution;  // empty vector !
  }

  // initialize the solution vector with 1.
  solution.assign(Nchannels, 1.);

  int ievent, i, j;

  // if normalization flag is set, normalize energies
  float sumOverEnergy;
  if (normaliseFlag) {
    float scale = 0.;

    std::cout << "GenericMinL3Algorithm::iterate(): Normalising event data" << std::endl;

    for (i = 0; i < Nevents; i++) {
      sumOverEnergy = 0.;
      for (j = 0; j < Nchannels; j++) {
        sumOverEnergy += eventMatrix[i][j];
      }
      sumOverEnergy /= myEnergyVector[i];
      scale += sumOverEnergy;
    }
    scale /= Nevents;
    std::cout << "  Normalisation = " << scale << std::endl;

    for (i = 0; i < Nevents; i++) {
      myEnergyVector[i] *= scale;
    }
  }  // end normalize energies

  // This is where the real work goes on...
  float sum25, invsum25;
  float w;                                  // weight for event
  std::vector<float> wsum(Nchannels, 0.);   // sum of weights for a crystal
  std::vector<float> Ewsum(Nchannels, 0.);  // sum of products of weight*Etrue/E25

  // Loop over events
  for (ievent = 0; ievent < Nevents; ievent++) {
    // Loop over the 5x5 to find the sum
    sum25 = 0.;

    for (i = 0; i < Nchannels; i++) {
      sum25 += eventMatrix[ievent][i];
    }  //*calibs[i];

    if (sum25 != 0.) {
      invsum25 = 1 / sum25;
      // Loop over the 5x5 again and calculate the weights for each xtal
      for (i = 0; i < Nchannels; i++) {
        w = eventMatrix[ievent][i] * invsum25;  // * calibs[i]
        wsum[i] += w;
        Ewsum[i] += (w * myEnergyVector[ievent] * invsum25);
      }
    } else {
      std::cout << " Debug: dropping null event: " << ievent << std::endl;
    }

  }  // end Loop over events

  // Apply correction factors to all channels not in the margin
  for (i = 0; i < Nchannels; i++) {
    if (wsum[i] != 0.) {
      solution[i] *= Ewsum[i] / wsum[i];
    } else {
      std::cout << "warning - no event data for crystal index " << i << std::endl;
    }
  }

  return solution;
}