FastLineRecognition Class Reference

Class performing optimized hough transform to recognize lines. More...

#include <FastLineRecognition.h>

Classes
struct	Cluster
	cluster of intersection points More...
struct	GeomData
struct	Point

Public Member Functions
	FastLineRecognition (double cw_a=0., double cw_b=0.)
void	getPatterns (const edm::DetSetVector< TotemRPRecHit > &input, double _z0, double threshold, edm::DetSet< TotemRPUVPattern > &patterns)
void	resetGeometry (const CTPPSGeometry *_g)
	~FastLineRecognition ()

Private Member Functions
GeomData	getGeomData (unsigned int id)
	expects raw detector id More...
bool	getOneLine (const std::vector< Point > &points, double threshold, Cluster &result)

Private Attributes
double	chw_a
	cluster half widths in a and b More...
double	chw_b
const CTPPSGeometry *	geometry
	pointer to the geometry More...
std::map< unsigned int, GeomData >	geometryMap
	map: raw detector id –> GeomData More...
double	threshold
	weight threshold for accepting pattern candidates (clusters) More...
double	z0
	"typical" z More...

Static Private Attributes
static const double	sigma0 = 66E-3/sqrt(12.)
	the uncertainty of 1-hit cluster, in mm More...

Detailed Description

Class performing optimized hough transform to recognize lines.

Definition at line 25 of file FastLineRecognition.h.

Constructor & Destructor Documentation

FastLineRecognition::FastLineRecognition	(	double	cw_a = 0.,
		double	cw_b = 0.
	)

Definition at line 60 of file FastLineRecognition.cc.

                                                                 :
  chw_a(cw_a/2.), chw_b(cw_b/2.), geometry(nullptr)
{
}

FastLineRecognition::~FastLineRecognition

(

)

Definition at line 67 of file FastLineRecognition.cc.

{
}

Member Function Documentation

FastLineRecognition::GeomData FastLineRecognition::getGeomData ( unsigned int  id )

private

expects raw detector id

Definition at line 73 of file FastLineRecognition.cc.

References EnergyCorrector::c, edmIntegrityCheck::d, geometryMap, triggerObjects_cff::id, FastLineRecognition::GeomData::s, and FastLineRecognition::GeomData::z.

Referenced by getPatterns().

{
  // result already buffered?
  map<unsigned int, GeomData>::iterator it = geometryMap.find(id);
  if (it != geometryMap.end())
    return it->second;

  // calculate it
  CLHEP::Hep3Vector d = geometry->localToGlobalDirection(id, CLHEP::Hep3Vector(0., 1., 0.));
  DetGeomDesc::Translation c = geometry->getSensor(TotemRPDetId(id))->translation();
  GeomData gd;
  gd.z = c.z();
  gd.s = d.x()*c.x() + d.y()*c.y();

  geometryMap[id] = gd;

  return gd;
}

bool FastLineRecognition::getOneLine ( const std::vector< Point > &  points, double  threshold, FastLineRecognition::Cluster &  result  )

private

gets the most significant pattern in the (remaining) points returns true when a pattern was found

Definition at line 187 of file FastLineRecognition.cc.

References a, funct::abs(), b, EnergyCorrector::c, chw_a, chw_b, fastPrimaryVertexProducer_cfi::clusters, relmon_rootfiles_spy::contents, gen::k, p1, p2, FastLineRecognition::Cluster::S1, FastLineRecognition::Cluster::Saw, FastLineRecognition::Cluster::Sbw, FastLineRecognition::Cluster::Sw, w, and w2.

Referenced by getPatterns(), and FastLineRecognition::Cluster::operator<().

{
#if CTPPS_DEBUG > 0
  printf("\tFastLineRecognition::getOneLine\n");
#endif

  if (points.size() < 2)
        return false;
  
  vector<Cluster> clusters;

  // go through all the combinations of measured points
  for (vector<Point>::const_iterator it1 = points.begin(); it1 != points.end(); ++it1)
  {
    if (!it1->usable)
      continue;

    for (vector<Point>::const_iterator it2 = it1; it2 != points.end(); ++it2)
    {
      if (!it2->usable)
        continue;

      const double &z1 = it1->z;
      const double &z2 = it2->z;

      if (z1 == z2)
        continue;

      const double &p1 = it1->h;
      const double &p2 = it2->h;
      
      const double &w1 = it1->w;
      const double &w2 = it2->w;

      // calculate intersection
      double a = (p2 - p1) / (z2 - z1);
      double b = p1 - z1 * a;
      double w = w1 + w2;

#if CTPPS_DEBUG > 0
      printf("\t\t\tz: 1=%+5.1f, 2=%+5.1f | U/V: 1=%+6.3f, 2=%+6.3f | a=%+6.3f rad, b=%+6.3f mm, w=%.1f\n", z1, z2, p1, p2, a, b, w);
#endif

      // add it to the appropriate cluster
      bool newCluster = true;
      for (unsigned int k = 0; k < clusters.size(); k++)
      {
        Cluster &c = clusters[k];
        if (c.S1 < 1. || c.Sw <= 0.)
          continue;

#if CTPPS_DEBUG > 0
        if (k < 10)
          printf("\t\t\t\ttest cluster %u at a=%+6.3f, b=%+6.3f : %+6.3f, %+6.3f : %i, %i\n", k, c.Saw/c.Sw, c.Sbw/c.Sw, 
            chw_a, chw_b,
            (std::abs(a - c.Saw/c.Sw) < chw_a), (std::abs(b - c.Sbw/c.Sw) < chw_b));
#endif

        if ((std::abs(a - c.Saw/c.Sw) < chw_a) && (std::abs(b - c.Sbw/c.Sw) < chw_b))
        {
          newCluster = false;
          clusters[k].add(& (*it1), & (*it2), a, b, w);
#if CTPPS_DEBUG > 0
          printf("\t\t\t\t--> cluster %u\n", k);
#endif
          break;
        }
      }

      // make new cluster
      if (newCluster)
      {
#if CTPPS_DEBUG > 0
        printf("\t\t\t\t--> new cluster %lu\n", clusters.size());
#endif
        clusters.push_back(Cluster());
        clusters.back().add(& (*it1), & (*it2), a, b, w);
      }
    }
  }

#if CTPPS_DEBUG > 0
  printf("\t\tclusters: %lu\n", clusters.size());
#endif

  // find the cluster with highest weight
  unsigned int mk = 0;
  double mw = -1.;
  for (unsigned int k = 0; k < clusters.size(); k++)
  {
    double w = 0;
    for (vector<const Point *>::iterator it = clusters[k].contents.begin(); it != clusters[k].contents.end(); ++it)
      w += (*it)->w;
    clusters[k].weight = w;

    if (w > mw)
    {
      mw = w;
      mk = k;
    }
  }

#if CTPPS_DEBUG > 0
  printf("\t\tmw = %.1f, mk = %u\n", mw, mk);
#endif

  // rerturn result
  if (mw >= threshold)
  {
    result = clusters[mk];

    return true;
  } else
    return false;
}

void FastLineRecognition::getPatterns	(	const edm::DetSetVector< TotemRPRecHit > &	input,
		double	_z0,
		double	threshold,
		edm::DetSet< TotemRPUVPattern > &	patterns
	)

Definition at line 94 of file FastLineRecognition.cc.

References TotemRPUVPattern::addHit(), EnergyCorrector::c, edm::DetSet< T >::clear(), FastLineRecognition::Cluster::contents, getGeomData(), getOneLine(), TotemRPRecHit::getPosition(), TotemRPRecHit::getSigma(), h, AlCaHLTBitMon_ParallelJobs::p, listBenchmarks::pattern, hiPixelPairStep_cff::points, edm::DetSet< T >::push_back(), FastLineRecognition::GeomData::s, FastLineRecognition::Cluster::Saw, FastLineRecognition::Cluster::Sbw, TotemRPUVPattern::setA(), TotemRPUVPattern::setB(), TotemRPUVPattern::setW(), sigma0, edm::DetSet< T >::size(), FastLineRecognition::Cluster::Sw, w, FastLineRecognition::Cluster::weight, z, FastLineRecognition::GeomData::z, and z0.

Referenced by TotemRPUVPatternFinder::recognizeAndSelect(), and resetGeometry().

{
  // build collection of points in the global coordinate system
  std::vector<Point> points;
  for (auto &ds : input)
  {
    unsigned int detId = ds.detId();

    for (auto &h : ds)
    {
      const TotemRPRecHit *hit = &h;
      const GeomData &gd = getGeomData(detId);
  
      double p = hit->getPosition() + gd.s;
      double z = gd.z - z0;
      double w = sigma0 / hit->getSigma();
  
      points.push_back(Point(detId, hit, p, z, w));
    }
  }

#if CTPPS_DEBUG > 0
  printf(">> FastLineRecognition::getPatterns(z0 = %E)\n", z0);
  printf(">>>>>>>>>>>>>>>>>>>\n");
#endif

  // reset output
  patterns.clear();

  Cluster c;
  while (getOneLine(points, threshold, c))
  {
    // convert cluster to pattern and save it
    TotemRPUVPattern pattern;
    pattern.setA(c.Saw/c.Sw);
    pattern.setB(c.Sbw/c.Sw);
    pattern.setW(c.weight);

#if CTPPS_DEBUG > 0
    printf("\tpoints of the selected cluster: %lu\n", c.contents.size());
#endif

    for (auto &pit : c.contents)
    { 
#if CTPPS_DEBUG > 0
      printf("\t\t%.1f\n", pit->z);
#endif
      pattern.addHit(pit->detId, *(pit->hit));
    }

    patterns.push_back(pattern);

#if CTPPS_DEBUG > 0
    unsigned int u_points_b = 0;
    for (vector<Point>::iterator dit = points.begin(); dit != points.end(); ++dit)
      if (dit->usable)
        u_points_b++;
    printf("\tusable points before: %u\n", u_points_b);
#endif

    // remove points belonging to the recognized line
    for (vector<const Point *>::iterator hit = c.contents.begin(); hit != c.contents.end(); ++hit)
    {
      for (vector<Point>::iterator dit = points.begin(); dit != points.end(); ++dit)
      {
        //printf("\t\t1: %.2f, %p vs. 2: %.2f, %p\n", (*hit)->z, (*hit)->hit, dit->z, dit->hit);
        if ((*hit)->hit == dit->hit)
        {
          dit->usable = false;
          //points.erase(dit);
          break;
        }
      }
    }

#if CTPPS_DEBUG > 0
    unsigned int u_points_a = 0;
    for (vector<Point>::iterator dit = points.begin(); dit != points.end(); ++dit)
      if (dit->usable)
        u_points_a++;
    printf("\tusable points after: %u\n", u_points_a);
#endif
  }

#if CTPPS_DEBUG > 0
  printf("patterns at end: %lu\n", patterns.size());
  printf("<<<<<<<<<<<<<<<<<<<\n");
#endif
}

void FastLineRecognition::resetGeometry ( const CTPPSGeometry *  _g )

inline

Definition at line 32 of file FastLineRecognition.h.

References geometryMap, getPatterns(), input, and threshold.

Referenced by TotemRPUVPatternFinder::produce().

    {
      geometry = _g;
      geometryMap.clear();
    }

Member Data Documentation

double FastLineRecognition::chw_a

private

cluster half widths in a and b

Definition at line 49 of file FastLineRecognition.h.

Referenced by getOneLine().

double FastLineRecognition::chw_b

private

Definition at line 49 of file FastLineRecognition.h.

Referenced by getOneLine().

const CTPPSGeometry* FastLineRecognition::geometry

private

pointer to the geometry

Definition at line 55 of file FastLineRecognition.h.

Referenced by Vispa.Gui.ConnectableWidget.ConnectableWidget::leaveEvent().

std::map<unsigned int, GeomData> FastLineRecognition::geometryMap

private

map: raw detector id –> GeomData

Definition at line 64 of file FastLineRecognition.h.

Referenced by getGeomData(), and resetGeometry().

const double FastLineRecognition::sigma0 = 66E-3/sqrt(12.)

staticprivate

the uncertainty of 1-hit cluster, in mm

Definition at line 43 of file FastLineRecognition.h.

Referenced by getPatterns().

double FastLineRecognition::threshold

private

weight threshold for accepting pattern candidates (clusters)

Definition at line 52 of file FastLineRecognition.h.

Referenced by utils.StatisticalTest::get_status(), and resetGeometry().

double FastLineRecognition::z0

private

"typical" z

Definition at line 46 of file FastLineRecognition.h.

Referenced by getPatterns().