SiStripApvShotCleaner.cc

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#include "RecoLocalTracker/SiStripClusterizer/interface/SiStripApvShotCleaner.h"
#include <algorithm>

//Uncomment the following #define to have print debug
//#define DEBUGME

SiStripApvShotCleaner::SiStripApvShotCleaner()
    : maxNumOfApvs(6),  //FED Default: 6 (i.e. max num apvs )
      stripsPerApv(128),
      stripsForMedian(64) {}

bool SiStripApvShotCleaner::clean(const edm::DetSet<SiStripDigi>& in,
                                  edm::DetSet<SiStripDigi>::const_iterator& scan,
                                  edm::DetSet<SiStripDigi>::const_iterator& end) {
  if (in.size() < 64)
    return false;

  if (loop(in)) {
    reset(scan, end);
    return true;
  }
  return false;
}

bool SiStripApvShotCleaner::loop(const edm::DetSet<SiStripDigi>& in) {
#ifdef DEBUGME
  std::stringstream ss;
  ss << __func__ << " working on detid " << in.detId() << " for a digi.size=" << in.size();
#endif

  shots_ = false;
  for (auto& val : shotApv_)
    val = false;

  cacheDetId = in.detId();

  //Find the position in the DetSet where the first strip of an apv should be inserted
  // needed to deduce if at least stripsForMedian strips per apv have been fired
  for (size_t i = 0; i <= maxNumOfApvs; ++i) {
    SiStripDigi d(i * stripsPerApv, 0);  //Fake digi, at the edge of the apv
    pFirstDigiOfApv[i] = std::lower_bound(in.begin(), in.end(), d);

    //if satisfied it means that the number of digis in the apv i-1 is above stripsForMedia -> apvShot
    if (i > 0 && pFirstDigiOfApv[i] - pFirstDigiOfApv[i - 1] > stripsForMedian) {
      shots_ = true;
      shotApv_[i - 1] = true;
#ifdef DEBUGME
      ss << " found an apv shot of " << pFirstDigiOfApv[i] - pFirstDigiOfApv[i - 1] << " digis in detid " << in.detId()
         << " apv " << i << std::endl;
#endif
    }

    //---------------------
    //Just for debug REMOVE
    /*
    if(i>0){
      ss << "detid " << in.detId() << " apv " << i-1 << " number digis " << pFirstDigiOfApv[i]-pFirstDigiOfApv[i-1] << " \t shot " << shotApv_[i-1] << std::endl;
      if(pFirstDigiOfApv[i]-pFirstDigiOfApv[i-1]>stripsForMedian-2){
    edm::DetSet<SiStripDigi>::const_iterator dig=pFirstDigiOfApv[i-1];
    while(dig!=pFirstDigiOfApv[i]){
      ss << "\t strip " << dig->strip() << " dig.adc " << dig->adc();
      dig++;
    }
    ss << std::endl;
      }
    }
    */
    //-------------------------------
  }

#ifdef DEBUGME
  edm::LogInfo("ApvShot") << ss.str();
#endif

  if (!shots_)
    return false;

  dumpInVector(pFirstDigiOfApv, maxNumOfApvs);
  return true;
}

void SiStripApvShotCleaner::dumpInVector(edm::DetSet<SiStripDigi>::const_iterator* pFirstDigiOfApv,
                                         size_t maxNumOfApvs) {
  vdigis.clear();
  //loop on Apvs and remove shots. if an apv doesn't have shots, copy it
  for (size_t i = 0; i < maxNumOfApvs; ++i) {
    apvDigis.clear();

    if (shotApv_[i]) {
      apvDigis.insert(apvDigis.end(), pFirstDigiOfApv[i], pFirstDigiOfApv[i + 1]);
      subtractCM();
      std::stable_sort(apvDigis.begin(), apvDigis.end());
      vdigis.insert(vdigis.end(), apvDigis.begin(), apvDigis.end());
    } else {
      vdigis.insert(vdigis.end(), pFirstDigiOfApv[i], pFirstDigiOfApv[i + 1]);
    }
  }

#ifdef DEBUGME
  std::stringstream ss;
  ss << "detid " << cacheDetId << " new digi.size " << vdigis.size() << "\n";
  for (size_t i = 0; i < vdigis.size(); ++i)
    ss << "\t " << i << " strip " << vdigis[i].strip() << " adc " << vdigis[i].adc();
  edm::LogInfo("ApvShot") << ss.str() << std::endl;
#endif
}

void SiStripApvShotCleaner::subtractCM() {
  //order by charge
  std::stable_sort(
      apvDigis.begin(), apvDigis.end(), [](SiStripDigi const& a, SiStripDigi const& b) { return a.adc() > b.adc(); });

  //ignore case where 64th strip is 0ADC
  if (apvDigis[stripsForMedian].adc() == 0) {
#ifdef DEBUGME
    std::stringstream ss;
    ss << "case with strip64=0 --> detid= " << cacheDetId << "\n";
    edm::LogInfo("ApvShot") << ss.str();
#endif
    return;
  }

  //Find the Median
  float CM = 0.5f * (apvDigis[stripsForMedian].adc() + apvDigis[stripsForMedian - 1].adc());

  if (CM <= 0)
    return;

  //Subtract the median
  const bool is10bit = apvDigis[0].adc() > 255;  // approximation; definitely 10bit in this case
  size_t i = 0;
  for (; i < stripsForMedian && apvDigis[i].adc() > CM; ++i) {
    const uint16_t adc =
        ((apvDigis[i].adc() > 253) && !is10bit) ? apvDigis[i].adc() : (uint16_t)(apvDigis[i].adc() - CM);
    apvDigis[i] = SiStripDigi(apvDigis[i].strip(), adc);
  }
  apvDigis.resize(i);

#ifdef DEBUGME
  std::stringstream ss;
  ss << "[subtractCM] detid " << cacheDetId << "  CM is " << CM << " the remaining strips after CM subtraction are  "
     << i;
  edm::LogInfo("ApvShot") << ss.str();
#endif
}

void SiStripApvShotCleaner::reset(edm::DetSet<SiStripDigi>::const_iterator& a,
                                  edm::DetSet<SiStripDigi>::const_iterator& b) {
  pDetSet.reset(new edm::DetSet<SiStripDigi>(cacheDetId));
  pDetSet->data.swap(vdigis);
  a = pDetSet->begin();
  b = pDetSet->end();
}