#include <DAClusterizerInZ.h>

Inheritance diagram for DAClusterizerInZ:

Classes
struct	track_t
struct	vertex_t
Public Member Functions
double	beta0 (const double betamax, std::vector< track_t > &tks, std::vector< vertex_t > &y) const
std::vector< std::vector < reco::TransientTrack > >	clusterize (const std::vector< reco::TransientTrack > &tracks) const
	DAClusterizerInZ (const edm::ParameterSet &conf)
void	dump (const double beta, const std::vector< vertex_t > &y, const std::vector< track_t > &tks, const int verbosity=0) const
double	Eik (const track_t &t, const vertex_t &k) const
std::vector< track_t >	fill (const std::vector< reco::TransientTrack > &tracks) const
bool	merge (std::vector< vertex_t > &, int) const
bool	purge (std::vector< vertex_t > &, std::vector< track_t > &, double &, const double) const
void	splitAll (std::vector< track_t > &tks, std::vector< vertex_t > &y) const
double	update (double beta, std::vector< track_t > &tks, std::vector< vertex_t > &y, double &) const
double	update (double beta, std::vector< track_t > &tks, std::vector< vertex_t > &y) const
std::vector< TransientVertex >	vertices (const std::vector< reco::TransientTrack > &tracks, const int verbosity=0) const
Private Attributes
float	betamax_
float	betastop_
double	coolingFactor_
int	maxIterations_
double	mu0_
bool	verbose_
float	vertexSize_

Detailed Description

Description: separates event tracks into clusters along the beam line

Definition at line 21 of file DAClusterizerInZ.h.

Constructor & Destructor Documentation

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

Definition at line 344 of file DAClusterizerInZ.cc.

References gather_cfg::cout, edm::ParameterSet::getParameter(), edm::ParameterSet::getUntrackedParameter(), and builder_last_value_cfg::Tmin.

{
  // some defaults to avoid uninitialized variables
  verbose_= conf.getUntrackedParameter<bool>("verbose", false);
  betamax_=0.1;
  betastop_  =1.0;
  coolingFactor_=0.8;
  maxIterations_=100;
  vertexSize_=0.05;  // 0.5 mm
  mu0_=4.0;   // Adaptive Fitter uses 3.0 but that appears to be a bit tight here sometimes

  // configure

  double Tmin = conf.getParameter<double>("Tmin");
  vertexSize_ = conf.getParameter<double>("vertexSize");
  coolingFactor_ = conf.getParameter<double>("coolingFactor");
  maxIterations_=100;
  if (Tmin==0){
    cout << "DAClusterizerInZ: invalid Tmin" << Tmin << "  reset do default " << 1./betamax_ << endl;
  }else{
    betamax_ = 1./Tmin;
  }

}

Member Function Documentation

double DAClusterizerInZ::beta0	(	const double	betamax,
		std::vector< track_t > &	tks,
		std::vector< vertex_t > &	y
	)		const

Definition at line 265 of file DAClusterizerInZ.cc.

References a, b, i, gen::k, funct::log(), nt, and funct::pow().

                                     {
  
  double T0=0;  // max Tc for beta=0
  // estimate critical temperature from beta=0 (T=inf)
  unsigned int nt=tks.size();

  for(vector<vertex_t>::iterator k=y.begin(); k!=y.end(); k++){

    // vertex fit at T=inf 
    double sumwz=0;
    double sumw=0;
    for(unsigned int i=0; i<nt; i++){
      double w=tks[i].pi/tks[i].dz2;
      sumwz+=w*tks[i].z;
      sumw +=w;
    }
    k->z=sumwz/sumw;

    // estimate Tcrit, eventually do this in the same loop
    double a=0, b=0;
    for(unsigned int i=0; i<nt; i++){
      double dx=tks[i].z-(k->z);
      double w=tks[i].pi/tks[i].dz2;
      a+=w*pow(dx,2)/tks[i].dz2;
      b+=w;
    }
    double Tc= 2.*a/b;  // the critical temperature of this vertex
    if(Tc>T0) T0=Tc;
  }// vertex loop (normally there should be only one vertex at beta=0)
  
  if (T0>1./betamax){
    return betamax/pow(coolingFactor_, int(log(T0*betamax)/log(coolingFactor_))-1 );
  }else{
    // ensure at least one annealing step
    return betamax/coolingFactor_;
  }
}

std::vector< std::vector<reco::TransientTrack> > DAClusterizerInZ::clusterize ( const std::vector< reco::TransientTrack > & tracks ) const [virtual]

Implements TrackClusterizerInZ.

void DAClusterizerInZ::dump	(	const double	beta,
		const std::vector< vertex_t > &	y,
		const std::vector< track_t > &	tks,
		const int	verbosity = `0`
	)		const

double DAClusterizerInZ::Eik	(	const track_t &	t,
		const vertex_t &	k
	)		const

Definition at line 59 of file DAClusterizerInZ.cc.

References DAClusterizerInZ::track_t::dz2, funct::pow(), DAClusterizerInZ::vertex_t::z, and DAClusterizerInZ::track_t::z.

                                                                      {
  return pow(t.z-k.z,2)/t.dz2;
}

std::vector<track_t> DAClusterizerInZ::fill ( const std::vector< reco::TransientTrack > & tracks ) const

bool DAClusterizerInZ::merge	(	std::vector< vertex_t > &	,
		int
	)		const

bool DAClusterizerInZ::purge	(	std::vector< vertex_t > &	,
		std::vector< track_t > &	,
		double &	,
		const double
	)		const

void DAClusterizerInZ::splitAll	(	std::vector< track_t > &	tks,
		std::vector< vertex_t > &	y
	)		const

Definition at line 310 of file DAClusterizerInZ.cc.

References ExpressReco_HICollisions_FallBack::e, epsilon, gen::k, DAClusterizerInZ::vertex_t::pk, and DAClusterizerInZ::vertex_t::z.

                               {


  double epsilon=1e-3;      // split all single vertices by 10 um 
  double zsep=2*epsilon;    // split vertices that are isolated by at least zsep (vertices that haven't collapsed)
  vector<vertex_t> y1;

  for(vector<vertex_t>::iterator k=y.begin(); k!=y.end(); k++){
    if ( ( (k==y.begin())|| (k-1)->z < k->z - zsep) && (((k+1)==y.end()  )|| (k+1)->z > k->z + zsep)) { 
      // isolated prototype, split
      vertex_t vnew;
      vnew.z  = k->z -epsilon;
      (*k).z  = k->z+epsilon;
      vnew.pk= 0.5* (*k).pk;
      (*k).pk= 0.5* (*k).pk;
      y1.push_back(vnew);
      y1.push_back(*k);

    }else if( y1.empty() || (y1.back().z < k->z -zsep)){
      y1.push_back(*k);
    }else{
      y1.back().z -=epsilon;
      k->z+=epsilon;
      y1.push_back(*k);
    }
  }// vertex loop
  
  y=y1;
}