#include <TotemTimingRecHitProducerAlgorithm.h>

Classes
struct	RegressionResults

Public Member Functions
void	build (const CTPPSGeometry *, const edm::DetSetVector< TotemTimingDigi > &, edm::DetSetVector< TotemTimingRecHit > &)

	TotemTimingRecHitProducerAlgorithm (const edm::ParameterSet &conf)

Private Member Functions
float	constantFractionDiscriminator (const std::vector< float > &time, const std::vector< float > &data)

int	fastDiscriminator (const std::vector< float > &data, const float &threshold) const

RegressionResults	simplifiedLinearRegression (const std::vector< float > &time, const std::vector< float > &data, const unsigned int start_at, const unsigned int points) const

Private Attributes
int	baselinePoints_

double	cfdFraction_

double	hysteresis_

double	lowPassFrequency_

TotemTimingRecHit::TimingAlgorithm	mode_

TotemTimingConversions	sampicConversions_

double	saturationLimit_

int	smoothingPoints_

Static Private Attributes
static const float	SINC_COEFFICIENT = std::acos(-1) * 2 / 7.8

Detailed Description

Definition at line 28 of file TotemTimingRecHitProducerAlgorithm.h.

Constructor & Destructor Documentation

TotemTimingRecHitProducerAlgorithm::TotemTimingRecHitProducerAlgorithm ( const edm::ParameterSet & conf )

Definition at line 19 of file TotemTimingRecHitProducerAlgorithm.cc.

     : sampicConversions_(iConfig.getParameter<std::string>("calibrationFile")),
       baselinePoints_(iConfig.getParameter<int>("baselinePoints")),
       saturationLimit_(iConfig.getParameter<double>("saturationLimit")),
       cfdFraction_(iConfig.getParameter<double>("cfdFraction")),
       smoothingPoints_(iConfig.getParameter<int>("smoothingPoints")),
       lowPassFrequency_(iConfig.getParameter<double>("lowPassFrequency")),
       hysteresis_(iConfig.getParameter<double>("hysteresis")) {}

Member Function Documentation

void TotemTimingRecHitProducerAlgorithm::build	(	const CTPPSGeometry *	geom,
		const edm::DetSetVector< TotemTimingDigi > &	input,
		edm::DetSetVector< TotemTimingRecHit > &	output
	)

Definition at line 29 of file TotemTimingRecHitProducerAlgorithm.cc.

References baselinePoints_, TotemTimingRecHit::CFD, constantFractionDiscriminator(), data, edm::DetSetVector< T >::find_or_insert(), CTPPSGeometry::getSensorNoThrow(), TotemTimingConversions::getTimeSamples(), TotemTimingConversions::getTriggerTime(), TotemTimingConversions::getVoltSamples(), mps_fire::i, mode_, TotemTimingRecHit::NO_T_AVAILABLE, DetGeomDesc::params(), DetGeomDesc::parentZPosition(), edm::DetSet< T >::push_back(), sampicConversions_, saturationLimit_, simplifiedLinearRegression(), lumiQTWidget::t, ntuplemaker::time, and DetGeomDesc::translation().

Referenced by TotemTimingRecHitProducer::produce().

                                                 {
   for (const auto &vec : input) {
     const TotemTimingDetId detid(vec.detId());
 
     float x_pos = 0.0f, y_pos = 0.0f, z_pos = 0.0f, x_width = 0.0f, y_width = 0.0f, 
           z_width = 0.0f;
 
     // retrieve the geometry element associated to this DetID ( if present )
     const DetGeomDesc *det = geom->getSensorNoThrow(detid);
 
     if (det) {
       x_pos = det->translation().x(), y_pos = det->translation().y();
       z_pos = det->parentZPosition(); // retrieve the plane position;
 
       x_width = 2.0 * det->params()[0], // parameters stand for half the size
       y_width = 2.0 * det->params()[1],
       z_width = 2.0 * det->params()[2];
     } else
       edm::LogWarning("TotemTimingRecHitProducerAlgorithm")
           << "Failed to retrieve a sensor for " << detid;
 
     edm::DetSet<TotemTimingRecHit> &rec_hits = output.find_or_insert(detid);
 
     for (const auto &digi : vec) {
       const float triggerCellTimeInstant(
           sampicConversions_.getTriggerTime(digi));
       const std::vector<float> time(sampicConversions_.getTimeSamples(digi));
       std::vector<float> data(sampicConversions_.getVoltSamples(digi));
 
       auto max_it = std::max_element(data.begin(), data.end());
 
       RegressionResults baselineRegression =
           simplifiedLinearRegression(time, data, 0, baselinePoints_);
 
       // remove baseline
       std::vector<float> dataCorrected(data.size());
       for (unsigned int i = 0; i < data.size(); ++i)
         dataCorrected[i] = data[i] -
                    (baselineRegression.q + baselineRegression.m * time[i]);
       auto max_corrected_it =
           std::max_element(dataCorrected.begin(), dataCorrected.end());
 
       float t = TotemTimingRecHit::NO_T_AVAILABLE;
       if (*max_it < saturationLimit_)
         t = constantFractionDiscriminator(time, dataCorrected);
 
       mode_ = TotemTimingRecHit::CFD;
 
       rec_hits.push_back(TotemTimingRecHit(
           x_pos, x_width, y_pos, y_width, z_pos, z_width, // spatial information
           t, triggerCellTimeInstant, .0, *max_corrected_it,
           baselineRegression.rms, mode_));
     }
   }
 }

float TotemTimingRecHitProducerAlgorithm::constantFractionDiscriminator	(	const std::vector< float > &	time,
		const std::vector< float > &	data
	)

private

Definition at line 163 of file TotemTimingRecHitProducerAlgorithm.cc.

References baselinePoints_, cfdFraction_, fastDiscriminator(), mps_fire::i, createfilelist::int, lowPassFrequency_, SiStripPI::max, TotemTimingRecHit::NO_T_AVAILABLE, funct::sin(), SINC_COEFFICIENT, smoothingPoints_, lumiQTWidget::t, electronIdCutBased_cfi::threshold, and x.

Referenced by build().

                                                                 {
   std::vector<float> dataProcessed(data);
   if (lowPassFrequency_ != 0) {
     // Smoothing
     for (int i = 0; i < (int)data.size(); ++i) {
       for (int j = -smoothingPoints_ / 2;
            j <= +smoothingPoints_ / 2; ++j) {
         if ((i + j) >= 0 && (i + j) < (int)data.size() && j != 0) {
           float x = SINC_COEFFICIENT * lowPassFrequency_ * j;
           dataProcessed[i] += data[i + j] * std::sin(x) / x;
         }
       }
     }
   }
   auto max_it = std::max_element(dataProcessed.begin(), dataProcessed.end());
   float max = *max_it;
 
   float threshold = cfdFraction_ * max;
   int indexOfThresholdCrossing = fastDiscriminator(dataProcessed, threshold);
 
   float t = TotemTimingRecHit::NO_T_AVAILABLE;
   if (indexOfThresholdCrossing >= baselinePoints_ &&
       indexOfThresholdCrossing < (int)time.size()) {
     t = (time[indexOfThresholdCrossing - 1] -
          time[indexOfThresholdCrossing]) /
             (dataProcessed[indexOfThresholdCrossing - 1] -
              dataProcessed[indexOfThresholdCrossing]) *
             (threshold - dataProcessed[indexOfThresholdCrossing]) +
         time[indexOfThresholdCrossing];
   }
 
   return t;
 }

int TotemTimingRecHitProducerAlgorithm::fastDiscriminator	(	const std::vector< float > &	data,
		const float &	threshold
	)		const

private

Definition at line 131 of file TotemTimingRecHitProducerAlgorithm.cc.

References hysteresis_, and mps_fire::i.

Referenced by constantFractionDiscriminator().

                                                                 {
   int threholdCrossingIndex = -1;
   bool above = false;
   bool lockForHysteresis = false;
 
   for (unsigned int i = 0; i < data.size(); ++i) {
     // Look for first edge
     if (!above && !lockForHysteresis && data[i] > threshold) {
       threholdCrossingIndex = i;
       above = true;
       lockForHysteresis = true;
     }
     if (above && lockForHysteresis) // NOTE: not else if!, "above" can be set in
                                     // the previous if
     {
       // Lock until above threshold_+hysteresis
       if (lockForHysteresis && data[i] > threshold + hysteresis_) {
         lockForHysteresis = false;
       }
       // Ignore noise peaks
       if (lockForHysteresis && data[i] < threshold) {
         above = false;
         lockForHysteresis = false;
         threholdCrossingIndex = -1; // assigned because of noise
       }
     }
   }
 
   return threholdCrossingIndex;
 }

TotemTimingRecHitProducerAlgorithm::RegressionResults TotemTimingRecHitProducerAlgorithm::simplifiedLinearRegression	(	const std::vector< float > &	time,
		const std::vector< float > &	data,
		const unsigned int	start_at,
		const unsigned int	points
	)		const

private

Definition at line 88 of file TotemTimingRecHitProducerAlgorithm.cc.

References mps_fire::i, TotemTimingRecHitProducerAlgorithm::RegressionResults::m, min(), GetRecoTauVFromDQM_MC_cff::next, hiPixelPairStep_cff::points, funct::pow(), TotemTimingRecHitProducerAlgorithm::RegressionResults::q, mps_update::results, TotemTimingRecHitProducerAlgorithm::RegressionResults::rms, mathSSE::sqrt(), fftjetcommon_cfi::sx, fftjetcommon_cfi::sy, and relativeConstraints::value.

Referenced by build().

                                                                   {
   RegressionResults results;
   if (time.size() != data.size()) {
     return results;
   }
   if (start_at > time.size()) {
     return results;
   }
   unsigned int stop_at = std::min((unsigned int)time.size(), start_at + points);
   unsigned int realPoints = stop_at - start_at;
   auto t_begin = std::next(time.begin(), start_at);
   auto t_end = std::next(time.begin(), stop_at);
   auto d_begin = std::next(data.begin(), start_at);
   auto d_end = std::next(data.begin(), stop_at);
 
   float sx = .0f;
   std::for_each(t_begin, t_end, [&](float value) { sx += value; });
   float sxx = .0f;
   std::for_each(t_begin, t_end, [&](float value) { sxx += value * value; });
 
   float sy = .0f;
   std::for_each(d_begin, d_end, [&](float value) { sy += value; });
   float syy = .0f;
   std::for_each(d_begin, d_end, [&](float value) { syy += value * value; });
 
   float sxy = .0f;
   for (unsigned int i = 0; i < realPoints; ++i)
     sxy += (time[i]) * (data[i]);
 
   // y = mx + q
   results.m = (sxy * realPoints - sx * sy) / (sxx * realPoints - sx * sx);
   results.q = sy / realPoints - results.m * sx / realPoints;
 
   float correctedSyy = .0f;
   for (unsigned int i = 0; i < realPoints; ++i)
     correctedSyy += pow(data[i] - (results.m * time[i] + results.q), 2);
   results.rms = sqrt(correctedSyy / realPoints);
 
   return results;
 }