hgcalsimclustertime Namespace Reference

Functions
float	fixSizeHighestDensity (std::vector< float > &t, float deltaT=0.210, float timeWidthBy=0.5)

Function Documentation

float hgcalsimclustertime::fixSizeHighestDensity	(	std::vector< float > &	t,
		float	deltaT = 0.210,
		float	timeWidthBy = 0.5
	)

Definition at line 21 of file ComputeClusterTime.h.

References funct::abs(), HltBtagPostValidation_cff::c, HLT_2018_cff::distance, EgammaValidation_cff::num, command_line::start, tolerance, and heppy_batch::val.

Referenced by RealisticSimClusterMapper::buildClusters(), and HGCalLayerClusterProducer::produce().

                                                       {
    float tolerance = 0.05f;
    std::sort(t.begin(), t.end());

    int max_elements = 0;
    int start_el = 0;
    int end_el = 0;
    float timeW = 0.f;

    for (auto start = t.begin(); start != t.end(); ++start) {
      const auto startRef = *start;
      int c = count_if(start, t.end(), [&](float el) { return el - startRef <= deltaT + tolerance; });
      if (c > max_elements) {
        max_elements = c;
        auto last_el = find_if_not(start, t.end(), [&](float el) { return el - startRef <= deltaT + tolerance; });
        auto val = *(--last_el);
        if (std::abs(deltaT - (val - startRef)) < tolerance) {
          tolerance = std::abs(deltaT - (val - startRef));
        }
        start_el = distance(t.begin(), start);
        end_el = distance(t.begin(), last_el);
        timeW = val - startRef;
      }
    }

    // further adjust time width around the chosen one based on the hits density
    // proved to improve the resolution: get as many hits as possible provided they are close in time

    float HalfTimeDiff = timeW * timeWidthBy;
    float sum = 0.;
    int num = 0;
    int totSize = t.size();

    for (int ij = 0; ij <= start_el; ++ij) {
      if (t[ij] > (t[start_el] - HalfTimeDiff)) {
        for (int kl = ij; kl < totSize; ++kl) {
          if (t[kl] < (t[end_el] + HalfTimeDiff)) {
            sum += t[kl];
            ++num;
          } else
            break;
        }
        break;
      }
    }

    if (num == 0)
      return -99.;
    return sum / num;
  }