TwoTrackMinimumDistanceHelixHelix Class Reference

#include <TwoTrackMinimumDistanceHelixHelix.h>

Public Member Functions
bool	calculate (const GlobalTrajectoryParameters &, const GlobalTrajectoryParameters &, const float qual=.001)
double	firstAngle () const
std::pair< double, double >	pathLength () const
std::pair< GlobalPoint, GlobalPoint >	points () const
double	secondAngle () const
	TwoTrackMinimumDistanceHelixHelix ()
	~TwoTrackMinimumDistanceHelixHelix ()

Private Member Functions
void	finalPoints ()
bool	oneIteration (double &, double &)
bool	updateCoeffs (const GlobalPoint &, const GlobalPoint &)

Private Attributes
double	pathG
double	pathH
GlobalPoint	pointG
GlobalPoint	pointH
bool	pointsUpdated
double	thea
double	theb
double	thec1
double	thec2
double	thecospG
double	thecospG0
double	thecospH
double	thecospH0
double	thed1
double	thed2
double	thee1
double	thee2
GlobalTrajectoryParameters const *	theG
double	theg
GlobalTrajectoryParameters const *	theH
double	theh
int	themaxiter
double	themaxjump
double	thepG
double	thepG0
double	thepH
double	thepH0
double	thesingjacI
double	thesinpG
double	thesinpG0
double	thesinpH
double	thesinpH0
double	thetanlambdaG
double	thetanlambdaH

Detailed Description

This is a helper class for TwoTrackMinimumDistance. No user should need direct access to this class. It actually implements a Newton-Kantorowitsch method for finding the minimum distance between two tracks.

Definition at line 18 of file TwoTrackMinimumDistanceHelixHelix.h.

Constructor & Destructor Documentation

TwoTrackMinimumDistanceHelixHelix()

TwoTrackMinimumDistanceHelixHelix::TwoTrackMinimumDistanceHelixHelix

(

)

Definition at line 10 of file TwoTrackMinimumDistanceHelixHelix.cc.

    : theH(nullptr), theG(nullptr), pointsUpdated(false), themaxjump(20), thesingjacI(1. / 0.1), themaxiter(4) {}

~TwoTrackMinimumDistanceHelixHelix()

TwoTrackMinimumDistanceHelixHelix::~TwoTrackMinimumDistanceHelixHelix

(

)

Definition at line 13 of file TwoTrackMinimumDistanceHelixHelix.cc.

{}

Member Function Documentation

calculate()

bool TwoTrackMinimumDistanceHelixHelix::calculate	(	const GlobalTrajectoryParameters &	G,
		const GlobalTrajectoryParameters &	H,
		const float	qual = .001
	)

Definition at line 112 of file TwoTrackMinimumDistanceHelixHelix.cc.

References finalPoints(), cmssw_cycle_finder::G, data-class-funcs::H, edm::isNotFinite(), oneIteration(), pointsUpdated, GlobalTrajectoryParameters::position(), theG, theg, theH, theh, themaxiter, themaxjump, thepG, thepG0, thepH, thepH0, and updateCoeffs().

                                                                    {
  pointsUpdated = false;
  theG = &G;
  theH = &H;
  bool retval = false;

  if (updateCoeffs(theG->position(), theH->position())) {
    finalPoints();
    return true;
  }

  thepG = thepG0;
  thepH = thepH0;

  int counter = 0;
  double pH = 0;
  double pG = 0;
  do {
    retval = oneIteration(pG, pH);
    if (edm::isNotFinite(pG) || edm::isNotFinite(pH))
      retval = true;
    if (counter++ > themaxiter)
      retval = true;
  } while ((!retval) && (fabs(pG) > qual || fabs(pH) > qual));
  if (fabs(theg * (thepG - thepG0)) > themaxjump)
    retval = true;
  if (fabs(theh * (thepH - thepH0)) > themaxjump)
    retval = true;

  finalPoints();

  return retval;
}

finalPoints()

void TwoTrackMinimumDistanceHelixHelix::finalPoints ( )

private

Definition at line 148 of file TwoTrackMinimumDistanceHelixHelix.cc.

References funct::cos(), pathG, pathH, pointG, pointH, pointsUpdated, GlobalTrajectoryParameters::position(), funct::sin(), mathSSE::sqrt(), thecospG0, thecospH0, theG, theg, theH, theh, thepG, thepG0, thepH, thepH0, thesinpG0, thesinpH0, thetanlambdaG, and thetanlambdaH.

Referenced by calculate().

                                                    {
  if (pointsUpdated)
    return;
  GlobalVector tmpG(sin(thepG) - thesinpG0, -cos(thepG) + thecospG0, thetanlambdaG * (thepG - thepG0));
  pointG = theG->position() + theg * tmpG;
  pathG = (thepG - thepG0) * (theg * sqrt(1 + thetanlambdaG * thetanlambdaG));

  GlobalVector tmpH(sin(thepH) - thesinpH0, -cos(thepH) + thecospH0, thetanlambdaH * (thepH - thepH0));
  pointH = theH->position() + theh * tmpH;
  pathH = (thepH - thepH0) * (theh * sqrt(1 + thetanlambdaH * thetanlambdaH));

  pointsUpdated = true;
}

firstAngle()

double TwoTrackMinimumDistanceHelixHelix::firstAngle ( ) const

inline

Definition at line 31 of file TwoTrackMinimumDistanceHelixHelix.h.

References thepG.

{ return thepG; }

oneIteration()

bool TwoTrackMinimumDistanceHelixHelix::oneIteration ( double &  dH, double &  dG  )

private

Definition at line 69 of file TwoTrackMinimumDistanceHelixHelix.cc.

References funct::cos(), funct::sin(), thea, theb, thec1, thec2, thecospG, thecospH, thed1, thed2, thee1, thee2, theg, theh, thepG, thepH, thesingjacI, thesinpG, thesinpH, ppsModifySingularModes_cfi::z1, and ppsModifySingularModes_cfi::z2.

Referenced by calculate().

                                                                           {
  thesinpH = sin(thepH);
  thecospH = cos(thepH);
  thesinpG = sin(thepG);
  thecospG = cos(thepG);

  const double A11 = theh * (-thesinpH * (thea - theg * thesinpG) + thecospH * (theb + theg * thecospG) + thec1);
  if (A11 < 0) {
    return true;
  };
  const double A22 = -theg * (-thesinpG * (thea + theh * thesinpH) + thecospG * (theb - theh * thecospH) + thec2);
  if (A22 < 0) {
    return true;
  };
  const double A12 = theh * (-theg * thecospG * thecospH - theg * thesinpH * thesinpG + thed1);
  const double A21 = -theg * (theh * thecospG * thecospH + theh * thesinpH * thesinpG + thed2);
  const double detaI = 1. / (A11 * A22 - A12 * A21);
  const double z1 = theh * (thecospH * (thea - theg * thesinpG) + thesinpH * (theb + theg * thecospG) + thec1 * thepH +
                            thed1 * thepG + thee1);
  const double z2 = -theg * (thecospG * (thea + theh * thesinpH) + thesinpG * (theb - theh * thecospH) + thec2 * thepG +
                             thed2 * thepH + thee2);

  dH = (z1 * A22 - z2 * A12) * detaI;
  dG = (z2 * A11 - z1 * A21) * detaI;
  if (fabs(detaI) > thesingjacI) {
    return true;
  };

  thepH -= dH;
  thepG -= dG;
  return false;
}

pathLength()

std::pair<double, double> TwoTrackMinimumDistanceHelixHelix::pathLength ( ) const

inline

Definition at line 29 of file TwoTrackMinimumDistanceHelixHelix.h.

References pathG, and pathH.

{ return std::pair<double, double>(pathG, pathH); }

points()

std::pair<GlobalPoint, GlobalPoint> TwoTrackMinimumDistanceHelixHelix::points ( ) const

inline

Definition at line 27 of file TwoTrackMinimumDistanceHelixHelix.h.

References pointG, and pointH.

{ return std::pair<GlobalPoint, GlobalPoint>(pointG, pointH); }

secondAngle()

double TwoTrackMinimumDistanceHelixHelix::secondAngle ( ) const

inline

Definition at line 32 of file TwoTrackMinimumDistanceHelixHelix.h.

References thepH.

{ return thepH; }

updateCoeffs()

bool TwoTrackMinimumDistanceHelixHelix::updateCoeffs ( const GlobalPoint &  gpH, const GlobalPoint &  gpG  )

private

Definition at line 15 of file TwoTrackMinimumDistanceHelixHelix.cc.

References Matriplex::atan2(), GlobalTrajectoryParameters::charge(), MagneticField::inInverseGeV(), GlobalTrajectoryParameters::magneticField(), GlobalTrajectoryParameters::momentum(), PV3DBase< T, PVType, FrameType >::perp(), GlobalTrajectoryParameters::position(), thea, theb, thec1, thec2, thecospG0, thecospH0, thed1, thed2, thee1, thee2, theG, theg, theH, theh, thepG0, thepH0, thesinpG0, thesinpH0, thetanlambdaG, thetanlambdaH, PV3DBase< T, PVType, FrameType >::x(), PV3DBase< T, PVType, FrameType >::y(), and PV3DBase< T, PVType, FrameType >::z().

Referenced by calculate().

                                                                                                   {
  const double Bc2kH = theH->magneticField().inInverseGeV(gpH).z();
  const double Bc2kG = theG->magneticField().inInverseGeV(gpG).z();
  const double Ht = theH->momentum().perp();
  const double Gt = theG->momentum().perp();
  //  thelambdaH=asin ( theH->momentum().z() / Hn );

  if (Ht == 0. || Gt == 0.) {
    edm::LogWarning("TwoTrackMinimumDistanceHelixHelix") << "transverse momentum of input trajectory is zero.";
    return true;
  };

  if (theH->charge() == 0. || theG->charge() == 0.) {
    edm::LogWarning("TwoTrackMinimumDistanceHelixHelix") << "charge of input track is zero.";
    return true;
  };

  if (Bc2kG == 0.) {
    edm::LogWarning("TwoTrackMinimumDistanceHelixHelix") << "magnetic field at point " << gpG << " is zero.";
    return true;
  };

  if (Bc2kH == 0.) {
    edm::LogWarning("TwoTrackMinimumDistanceHelixHelix") << "magnetic field at point " << gpH << " is zero.";
    return true;
  };

  theh = Ht / (theH->charge() * Bc2kH);
  thesinpH0 = -theH->momentum().y() / (Ht);
  thecospH0 = -theH->momentum().x() / (Ht);
  thetanlambdaH = -theH->momentum().z() / (Ht);
  thepH0 = atan2(thesinpH0, thecospH0);

  // thelambdaG=asin ( theG->momentum().z()/( Gn ) );

  theg = Gt / (theG->charge() * Bc2kG);
  thesinpG0 = -theG->momentum().y() / (Gt);
  thecospG0 = -theG->momentum().x() / (Gt);
  thetanlambdaG = -theG->momentum().z() / (Gt);
  thepG0 = atan2(thesinpG0, thecospG0);

  thea = theH->position().x() - theG->position().x() + theg * thesinpG0 - theh * thesinpH0;
  theb = theH->position().y() - theG->position().y() - theg * thecospG0 + theh * thecospH0;
  thec1 = theh * thetanlambdaH * thetanlambdaH;
  thec2 = -theg * thetanlambdaG * thetanlambdaG;
  thed1 = -theg * thetanlambdaG * thetanlambdaH;
  thed2 = theh * thetanlambdaG * thetanlambdaH;
  thee1 = thetanlambdaH *
          (theH->position().z() - theG->position().z() - theh * thepH0 * thetanlambdaH + theg * thepG0 * thetanlambdaG);
  thee2 = thetanlambdaG *
          (theH->position().z() - theG->position().z() - theh * thepH0 * thetanlambdaH + theg * thepG0 * thetanlambdaG);
  return false;
}

Member Data Documentation

pathG

double TwoTrackMinimumDistanceHelixHelix::pathG

private

Definition at line 57 of file TwoTrackMinimumDistanceHelixHelix.h.

Referenced by finalPoints(), and pathLength().

pathH

double TwoTrackMinimumDistanceHelixHelix::pathH

private

Definition at line 57 of file TwoTrackMinimumDistanceHelixHelix.h.

Referenced by finalPoints(), and pathLength().

pointG

GlobalPoint TwoTrackMinimumDistanceHelixHelix::pointG

private

Definition at line 56 of file TwoTrackMinimumDistanceHelixHelix.h.

Referenced by finalPoints(), and points().

pointH

GlobalPoint TwoTrackMinimumDistanceHelixHelix::pointH

private

Definition at line 56 of file TwoTrackMinimumDistanceHelixHelix.h.

Referenced by finalPoints(), and points().

pointsUpdated

bool TwoTrackMinimumDistanceHelixHelix::pointsUpdated

private

Definition at line 58 of file TwoTrackMinimumDistanceHelixHelix.h.

Referenced by calculate(), and finalPoints().

thea

double TwoTrackMinimumDistanceHelixHelix::thea

private

Definition at line 44 of file TwoTrackMinimumDistanceHelixHelix.h.

Referenced by oneIteration(), and updateCoeffs().

theb

double TwoTrackMinimumDistanceHelixHelix::theb

private

Definition at line 44 of file TwoTrackMinimumDistanceHelixHelix.h.

Referenced by oneIteration(), and updateCoeffs().

thec1

double TwoTrackMinimumDistanceHelixHelix::thec1

private

Definition at line 44 of file TwoTrackMinimumDistanceHelixHelix.h.

Referenced by oneIteration(), and updateCoeffs().

thec2

double TwoTrackMinimumDistanceHelixHelix::thec2

private

Definition at line 44 of file TwoTrackMinimumDistanceHelixHelix.h.

Referenced by oneIteration(), and updateCoeffs().

thecospG

double TwoTrackMinimumDistanceHelixHelix::thecospG

private

Definition at line 55 of file TwoTrackMinimumDistanceHelixHelix.h.

Referenced by oneIteration().

thecospG0

double TwoTrackMinimumDistanceHelixHelix::thecospG0

private

Definition at line 47 of file TwoTrackMinimumDistanceHelixHelix.h.

Referenced by finalPoints(), and updateCoeffs().

thecospH

double TwoTrackMinimumDistanceHelixHelix::thecospH

private

Definition at line 55 of file TwoTrackMinimumDistanceHelixHelix.h.

Referenced by oneIteration().

thecospH0

double TwoTrackMinimumDistanceHelixHelix::thecospH0

private

Definition at line 48 of file TwoTrackMinimumDistanceHelixHelix.h.

Referenced by finalPoints(), and updateCoeffs().

thed1

double TwoTrackMinimumDistanceHelixHelix::thed1

private

Definition at line 44 of file TwoTrackMinimumDistanceHelixHelix.h.

Referenced by oneIteration(), and updateCoeffs().

thed2

double TwoTrackMinimumDistanceHelixHelix::thed2

private

Definition at line 44 of file TwoTrackMinimumDistanceHelixHelix.h.

Referenced by oneIteration(), and updateCoeffs().

thee1

double TwoTrackMinimumDistanceHelixHelix::thee1

private

Definition at line 44 of file TwoTrackMinimumDistanceHelixHelix.h.

Referenced by oneIteration(), and updateCoeffs().

thee2

double TwoTrackMinimumDistanceHelixHelix::thee2

private

Definition at line 44 of file TwoTrackMinimumDistanceHelixHelix.h.

Referenced by oneIteration(), and updateCoeffs().

theG

GlobalTrajectoryParameters const * TwoTrackMinimumDistanceHelixHelix::theG

private

Definition at line 42 of file TwoTrackMinimumDistanceHelixHelix.h.

Referenced by calculate(), finalPoints(), and updateCoeffs().

theg

double TwoTrackMinimumDistanceHelixHelix::theg

private

Definition at line 44 of file TwoTrackMinimumDistanceHelixHelix.h.

Referenced by calculate(), finalPoints(), oneIteration(), and updateCoeffs().

theH

GlobalTrajectoryParameters const* TwoTrackMinimumDistanceHelixHelix::theH

private

Definition at line 42 of file TwoTrackMinimumDistanceHelixHelix.h.

Referenced by calculate(), finalPoints(), and updateCoeffs().

theh

double TwoTrackMinimumDistanceHelixHelix::theh

private

Definition at line 44 of file TwoTrackMinimumDistanceHelixHelix.h.

Referenced by calculate(), finalPoints(), oneIteration(), and updateCoeffs().

themaxiter

int TwoTrackMinimumDistanceHelixHelix::themaxiter

private

Definition at line 61 of file TwoTrackMinimumDistanceHelixHelix.h.

Referenced by calculate().

themaxjump

double TwoTrackMinimumDistanceHelixHelix::themaxjump

private

Definition at line 60 of file TwoTrackMinimumDistanceHelixHelix.h.

Referenced by calculate().

thepG

double TwoTrackMinimumDistanceHelixHelix::thepG

private

Definition at line 53 of file TwoTrackMinimumDistanceHelixHelix.h.

Referenced by calculate(), finalPoints(), firstAngle(), and oneIteration().

thepG0

double TwoTrackMinimumDistanceHelixHelix::thepG0

private

Definition at line 49 of file TwoTrackMinimumDistanceHelixHelix.h.

Referenced by calculate(), finalPoints(), and updateCoeffs().

thepH

double TwoTrackMinimumDistanceHelixHelix::thepH

private

Definition at line 53 of file TwoTrackMinimumDistanceHelixHelix.h.

Referenced by calculate(), finalPoints(), oneIteration(), and secondAngle().

thepH0

double TwoTrackMinimumDistanceHelixHelix::thepH0

private

Definition at line 49 of file TwoTrackMinimumDistanceHelixHelix.h.

Referenced by calculate(), finalPoints(), and updateCoeffs().

thesingjacI

double TwoTrackMinimumDistanceHelixHelix::thesingjacI

private

Definition at line 60 of file TwoTrackMinimumDistanceHelixHelix.h.

Referenced by oneIteration().

thesinpG

double TwoTrackMinimumDistanceHelixHelix::thesinpG

private

Definition at line 54 of file TwoTrackMinimumDistanceHelixHelix.h.

Referenced by oneIteration().

thesinpG0

double TwoTrackMinimumDistanceHelixHelix::thesinpG0

private

Definition at line 47 of file TwoTrackMinimumDistanceHelixHelix.h.

Referenced by finalPoints(), and updateCoeffs().

thesinpH

double TwoTrackMinimumDistanceHelixHelix::thesinpH

private

Definition at line 54 of file TwoTrackMinimumDistanceHelixHelix.h.

Referenced by oneIteration().

thesinpH0

double TwoTrackMinimumDistanceHelixHelix::thesinpH0

private

Definition at line 48 of file TwoTrackMinimumDistanceHelixHelix.h.

Referenced by finalPoints(), and updateCoeffs().

thetanlambdaG

double TwoTrackMinimumDistanceHelixHelix::thetanlambdaG

private

Definition at line 46 of file TwoTrackMinimumDistanceHelixHelix.h.

Referenced by finalPoints(), and updateCoeffs().

thetanlambdaH

double TwoTrackMinimumDistanceHelixHelix::thetanlambdaH

private

Definition at line 46 of file TwoTrackMinimumDistanceHelixHelix.h.

Referenced by finalPoints(), and updateCoeffs().