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TwoTrackMinimumDistanceHelixHelix Class Reference

This is a helper class for TwoTrackMinimumDistance. More...

#include <TrackingTools/PatternTools/interface/TwoTrackMinimumDistanceHelixHelix.h>

List of all members.

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 () const
bool oneIteration (double &, double &) const
bool parallelTracks () const
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
double theg
GlobalTrajectoryParameters * theG
double theh
GlobalTrajectoryParameters * theH
double thelambdaG
double thelambdaH
int themaxiter
double themaxjump
double thepG
double thepG0
double thepH
double thepH0
double thesingjac
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 (  ) 

Definition at line 33 of file TwoTrackMinimumDistanceHelixHelix.cc.

00033                                                                     :
00034 theH(), theG(), pointsUpdated(false), themaxjump(20),thesingjac(.1), themaxiter(4)
00035 { }

TwoTrackMinimumDistanceHelixHelix::~TwoTrackMinimumDistanceHelixHelix (  ) 

Definition at line 37 of file TwoTrackMinimumDistanceHelixHelix.cc.

00037 {}

Member Function Documentation

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

Definition at line 152 of file TwoTrackMinimumDistanceHelixHelix.cc.

References counter(), oneIteration(), pointsUpdated, GlobalTrajectoryParameters::position(), theG, theg, theH, theh, themaxiter, themaxjump, thepG, thepG0, thepH, thepH0, and updateCoeffs().

Referenced by TwoTrackMinimumDistance::pointsHelixHelix().

00155 {
00156   pointsUpdated = false;
00157   theG= (GlobalTrajectoryParameters *) &G;
00158   theH= (GlobalTrajectoryParameters *) &H;
00159   bool retval=false;
00160 
00161   if ( updateCoeffs ( theG->position(), theH->position() ) )
00162   {
00163     return true;
00164   };
00165 
00166   thepG = thepG0;
00167   thepH = thepH0;
00168 
00169   int counter=0;
00170   double pH=0; double pG=0;
00171   do {
00172     retval=oneIteration ( pG, pH );
00173     if ( !finite(pG) || !finite(pH) ) retval=true;
00174     if ( counter++>themaxiter ) retval=true;
00175   } while ( (!retval) && ( fabs(pG) > qual || fabs(pH) > qual ));
00176   if ( fabs ( theg * ( thepG - thepG0 ) ) > themaxjump ) retval=true;
00177   if ( fabs ( theh * ( thepH - thepH0 ) ) > themaxjump ) retval=true;
00178   return retval;
00179 }

void TwoTrackMinimumDistanceHelixHelix::finalPoints (  )  const [private]

Definition at line 191 of file TwoTrackMinimumDistanceHelixHelix.cc.

References funct::cos(), pathG, pathH, pointG, pointH, pointsUpdated, GlobalTrajectoryParameters::position(), funct::sin(), funct::sqrt(), thecospG0, thecospH0, theG, theg, theH, theh, thepG, thepG0, thepH, thepH0, thesinpG0, thesinpH0, thetanlambdaG, thetanlambdaH, PV3DBase< T, PVType, FrameType >::x(), PV3DBase< T, PVType, FrameType >::y(), and PV3DBase< T, PVType, FrameType >::z().

Referenced by pathLength(), and points().

00192 {
00193   pointG = GlobalPoint (
00194       theG->position().x() + theg * ( sin ( thepG) - thesinpG0) ,
00195       theG->position().y() + theg * ( - cos ( thepG) + thecospG0 ),
00196       theG->position().z() + theg * ( thetanlambdaG * ( thepG- thepG0 ))
00197   );
00198   pathG = ( thepG- thepG0 ) * (theg*sqrt(1+thetanlambdaG*thetanlambdaG)) ;
00199 
00200   pointH = GlobalPoint (
00201       theH->position().x() + theh * ( sin ( thepH) - thesinpH0 ),
00202       theH->position().y() + theh * ( - cos ( thepH) + thecospH0 ),
00203       theH->position().z() + theh * ( thetanlambdaH * ( thepH- thepH0 ))
00204   );
00205   pathH = ( thepH- thepH0 ) * (theh*sqrt(1+thetanlambdaH*thetanlambdaH)) ;
00206   pointsUpdated = true;
00207 }

double TwoTrackMinimumDistanceHelixHelix::firstAngle (  )  const

Definition at line 181 of file TwoTrackMinimumDistanceHelixHelix.cc.

References thepG.

Referenced by TwoTrackMinimumDistance::firstAngle().

00182 {
00183   return thepG;
00184 }

bool TwoTrackMinimumDistanceHelixHelix::oneIteration ( double &  dH,
double &  dG 
) const [private]

Definition at line 108 of file TwoTrackMinimumDistanceHelixHelix.cc.

References A11, A12, A21, A22, funct::cos(), funct::sin(), thea, theb, thec1, thec2, thecospG, thecospH, thed1, thed2, thee1, thee2, theg, theh, thepG, thepH, thesingjac, thesinpG, and thesinpH.

Referenced by calculate().

00110 {
00111   thesinpH=sin(thepH);
00112   thecospH=cos(thepH);
00113   thesinpG=sin(thepG);
00114   thecospG=cos(thepG);
00115 
00116   const double A11= theh * ( - thesinpH * ( thea - theg * thesinpG ) +
00117       thecospH * ( theb + theg * thecospG ) + thec1);
00118   if (A11 < 0) { return true; };
00119   const double A22= -theg * (- thesinpG * ( thea + theh * thesinpH ) +
00120       thecospG*( theb - theh * thecospH ) + thec2);
00121   if (A22 < 0) { return true; };
00122   const double A12= theh * (-theg * thecospG * thecospH -
00123       theg * thesinpH * thesinpG + thed1);
00124   const double A21= -theg * (theh * thecospG * thecospH +
00125       theh * thesinpH * thesinpG + thed2);
00126   const double deta = A11 * A22 - A12 * A21;
00127   const double z1=theh * ( thecospH * ( thea - theg * thesinpG ) + thesinpH *
00128       ( theb + theg*thecospG ) + thec1 * thepH + thed1 * thepG + thee1);
00129   const double z2=-theg * (thecospG * ( thea + theh * thesinpH ) + thesinpG *
00130       ( theb - theh*thecospH ) + thec2 * thepG + thed2 * thepH + thee2);
00131   
00132   dH=( z1 * A22 - z2 * A12 ) / deta;
00133   dG=( z2 * A11 - z1 * A21 ) / deta;
00134   if ( fabs(deta) < thesingjac ) { return true; };
00135 
00136   thepH -= dH;
00137   thepG -= dG;
00138   return false;
00139 }

bool TwoTrackMinimumDistanceHelixHelix::parallelTracks (  )  const [inline, private]

Definition at line 141 of file TwoTrackMinimumDistanceHelixHelix.cc.

References GlobalTrajectoryParameters::charge(), GlobalTrajectoryParameters::momentum(), theG, theH, PV3DBase< T, PVType, FrameType >::x(), PV3DBase< T, PVType, FrameType >::y(), and PV3DBase< T, PVType, FrameType >::z().

00142 {
00143   bool retval=false;
00144   if (fabs(theH->momentum().x() - theG->momentum().x()) < .00000001 )
00145   if (fabs(theH->momentum().y() - theG->momentum().y()) < .00000001 )
00146   if (fabs(theH->momentum().z() - theG->momentum().z()) < .00000001 )
00147   if (theH->charge()==theG->charge()) retval=true;
00148   return retval;
00149 }

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

Definition at line 209 of file TwoTrackMinimumDistanceHelixHelix.cc.

References finalPoints(), pathG, pathH, and pointsUpdated.

Referenced by TwoTrackMinimumDistance::pathLength().

00210 {
00211   if (!pointsUpdated)finalPoints();
00212   return pair <double, double> ( pathG, pathH);
00213 }

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

Definition at line 215 of file TwoTrackMinimumDistanceHelixHelix.cc.

References finalPoints(), pointG, pointH, and pointsUpdated.

Referenced by TwoTrackMinimumDistance::pointsHelixHelix().

00217 {
00218   if (!pointsUpdated)finalPoints();
00219   return pair<GlobalPoint, GlobalPoint> (pointG, pointH);
00220 }

double TwoTrackMinimumDistanceHelixHelix::secondAngle (  )  const

Definition at line 186 of file TwoTrackMinimumDistanceHelixHelix.cc.

References thepH.

Referenced by TwoTrackMinimumDistance::secondAngle().

00187 {
00188   return thepH;
00189 }

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

Definition at line 39 of file TwoTrackMinimumDistanceHelixHelix.cc.

References GlobalTrajectoryParameters::charge(), MagneticField::inTesla(), PV3DBase< T, PVType, FrameType >::mag(), GlobalTrajectoryParameters::magneticField(), GlobalTrajectoryParameters::momentum(), GlobalTrajectoryParameters::position(), funct::sqrt(), square(), thea, theb, thec1, thec2, thecospG0, thecospH0, thed1, thed2, thee1, thee2, theG, theg, theH, theh, thelambdaG, thelambdaH, 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().

00041 {
00042 //  const double Bc2kH = MagneticField::inInverseGeV ( gpH ).z();
00043   const double Bc2kH = theH->magneticField().inTesla(gpH).z() * 2.99792458e-3;
00044 //  const double Bc2kG = MagneticField::inInverseGeV ( gpG ).z();
00045   const double Bc2kG = theG->magneticField().inTesla(gpG).z() * 2.99792458e-3;
00046   const double Hn= theH->momentum().mag();
00047   const double Gn= theG->momentum().mag();
00048   thelambdaH=asin ( theH->momentum().z() / Hn );
00049 
00050   if ( Hn == 0. || Gn == 0. )
00051   {
00052     edm::LogWarning ("TwoTrackMinimumDistanceHelixHelix")
00053       << "momentum of input trajectory is zero.";
00054     return true;
00055   };
00056 
00057   if ( theH->charge() == 0. || theG->charge() == 0. )
00058   {
00059     edm::LogWarning ("TwoTrackMinimumDistanceHelixHelix")
00060       << "charge of input track is zero.";
00061     return true;
00062   };
00063 
00064   if ( Bc2kG == 0. )
00065   {
00066     edm::LogWarning ("TwoTrackMinimumDistanceHelixHelix")
00067       << "magnetic field at point " << gpG << " is zero.";
00068     return true;
00069   };
00070 
00071   if ( Bc2kH == 0. )
00072   {
00073     edm::LogWarning ("TwoTrackMinimumDistanceHelixHelix")
00074       << "magnetic field at point " << gpH << " is zero.";
00075     return true;
00076   };
00077 
00078   theh= Hn / (theH->charge() * Bc2kH ) *
00079      sqrt( 1 - square ( ( theH->momentum().z() / Hn )));
00080   thesinpH0= - theH->momentum().y() / ( theH->charge() * Bc2kH * theh );
00081   thecospH0= - theH->momentum().x() / ( theH->charge() * Bc2kH * theh );
00082   thetanlambdaH = - theH->momentum().z() / ( theH->charge() * Bc2kH * theh);
00083   thepH0 = atan2 ( thesinpH0 , thecospH0 );
00084   thelambdaG=asin ( theG->momentum().z()/( Gn ) );
00085   theg= Gn / (theG->charge() * Bc2kG ) *
00086     sqrt( 1 - square ( ( theG->momentum().z() / Gn )));
00087   thesinpG0= - theG->momentum().y() / ( theG->charge()* Bc2kG * theg );
00088   thecospG0= - theG->momentum().x() / ( theG->charge() * Bc2kG * theg );
00089   thetanlambdaG = - theG->momentum().z() / ( theG->charge() * Bc2kG * theg);
00090 
00091   thepG0 = atan2 ( thesinpG0 , thecospG0 );
00092 
00093   thea=theH->position().x() - theG->position().x() + theg * thesinpG0 -
00094      theh * thesinpH0;
00095   theb=theH->position().y() - theG->position().y() - theg * thecospG0 +
00096      theh * thecospH0;
00097   thec1= theh * thetanlambdaH * thetanlambdaH;
00098   thec2= -theg * thetanlambdaG * thetanlambdaG;
00099   thed1= -theg * thetanlambdaG * thetanlambdaH;
00100   thed2= theh * thetanlambdaG * thetanlambdaH;
00101   thee1= thetanlambdaH * ( theH->position().z() - theG->position().z() -
00102        theh * thepH0 * thetanlambdaH + theg * thepG0 * thetanlambdaG );
00103   thee2= thetanlambdaG * ( theH->position().z() - theG->position().z() -
00104        theh * thepH0 * thetanlambdaH + theg * thepG0 * thetanlambdaG );
00105   return false;
00106 }

Member Data Documentation

double TwoTrackMinimumDistanceHelixHelix::pathG [mutable, private]

Definition at line 57 of file TwoTrackMinimumDistanceHelixHelix.h.

Referenced by finalPoints(), and pathLength().

double TwoTrackMinimumDistanceHelixHelix::pathH [mutable, private]

Definition at line 57 of file TwoTrackMinimumDistanceHelixHelix.h.

Referenced by finalPoints(), and pathLength().

GlobalPoint TwoTrackMinimumDistanceHelixHelix::pointG [mutable, private]

Definition at line 56 of file TwoTrackMinimumDistanceHelixHelix.h.

Referenced by finalPoints(), and points().

GlobalPoint TwoTrackMinimumDistanceHelixHelix::pointH [mutable, private]

Definition at line 56 of file TwoTrackMinimumDistanceHelixHelix.h.

Referenced by finalPoints(), and points().

bool TwoTrackMinimumDistanceHelixHelix::pointsUpdated [mutable, private]

Definition at line 58 of file TwoTrackMinimumDistanceHelixHelix.h.

Referenced by calculate(), finalPoints(), pathLength(), and points().

double TwoTrackMinimumDistanceHelixHelix::thea [private]

Definition at line 44 of file TwoTrackMinimumDistanceHelixHelix.h.

Referenced by oneIteration(), and updateCoeffs().

double TwoTrackMinimumDistanceHelixHelix::theb [private]

Definition at line 44 of file TwoTrackMinimumDistanceHelixHelix.h.

Referenced by oneIteration(), and updateCoeffs().

double TwoTrackMinimumDistanceHelixHelix::thec1 [private]

Definition at line 44 of file TwoTrackMinimumDistanceHelixHelix.h.

Referenced by oneIteration(), and updateCoeffs().

double TwoTrackMinimumDistanceHelixHelix::thec2 [private]

Definition at line 44 of file TwoTrackMinimumDistanceHelixHelix.h.

Referenced by oneIteration(), and updateCoeffs().

double TwoTrackMinimumDistanceHelixHelix::thecospG [mutable, private]

Definition at line 55 of file TwoTrackMinimumDistanceHelixHelix.h.

Referenced by oneIteration().

double TwoTrackMinimumDistanceHelixHelix::thecospG0 [private]

Definition at line 47 of file TwoTrackMinimumDistanceHelixHelix.h.

Referenced by finalPoints(), and updateCoeffs().

double TwoTrackMinimumDistanceHelixHelix::thecospH [mutable, private]

Definition at line 55 of file TwoTrackMinimumDistanceHelixHelix.h.

Referenced by oneIteration().

double TwoTrackMinimumDistanceHelixHelix::thecospH0 [private]

Definition at line 48 of file TwoTrackMinimumDistanceHelixHelix.h.

Referenced by finalPoints(), and updateCoeffs().

double TwoTrackMinimumDistanceHelixHelix::thed1 [private]

Definition at line 44 of file TwoTrackMinimumDistanceHelixHelix.h.

Referenced by oneIteration(), and updateCoeffs().

double TwoTrackMinimumDistanceHelixHelix::thed2 [private]

Definition at line 44 of file TwoTrackMinimumDistanceHelixHelix.h.

Referenced by oneIteration(), and updateCoeffs().

double TwoTrackMinimumDistanceHelixHelix::thee1 [private]

Definition at line 44 of file TwoTrackMinimumDistanceHelixHelix.h.

Referenced by oneIteration(), and updateCoeffs().

double TwoTrackMinimumDistanceHelixHelix::thee2 [private]

Definition at line 44 of file TwoTrackMinimumDistanceHelixHelix.h.

Referenced by oneIteration(), and updateCoeffs().

double TwoTrackMinimumDistanceHelixHelix::theg [private]

Definition at line 44 of file TwoTrackMinimumDistanceHelixHelix.h.

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

GlobalTrajectoryParameters * TwoTrackMinimumDistanceHelixHelix::theG [private]

Definition at line 42 of file TwoTrackMinimumDistanceHelixHelix.h.

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

double TwoTrackMinimumDistanceHelixHelix::theh [private]

Definition at line 44 of file TwoTrackMinimumDistanceHelixHelix.h.

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

GlobalTrajectoryParameters* TwoTrackMinimumDistanceHelixHelix::theH [private]

Definition at line 42 of file TwoTrackMinimumDistanceHelixHelix.h.

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

double TwoTrackMinimumDistanceHelixHelix::thelambdaG [private]

Definition at line 45 of file TwoTrackMinimumDistanceHelixHelix.h.

Referenced by updateCoeffs().

double TwoTrackMinimumDistanceHelixHelix::thelambdaH [private]

Definition at line 45 of file TwoTrackMinimumDistanceHelixHelix.h.

Referenced by updateCoeffs().

int TwoTrackMinimumDistanceHelixHelix::themaxiter [private]

Definition at line 61 of file TwoTrackMinimumDistanceHelixHelix.h.

Referenced by calculate().

double TwoTrackMinimumDistanceHelixHelix::themaxjump [private]

Definition at line 60 of file TwoTrackMinimumDistanceHelixHelix.h.

Referenced by calculate().

double TwoTrackMinimumDistanceHelixHelix::thepG [mutable, private]

Definition at line 53 of file TwoTrackMinimumDistanceHelixHelix.h.

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

double TwoTrackMinimumDistanceHelixHelix::thepG0 [private]

Definition at line 49 of file TwoTrackMinimumDistanceHelixHelix.h.

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

double TwoTrackMinimumDistanceHelixHelix::thepH [mutable, private]

Definition at line 53 of file TwoTrackMinimumDistanceHelixHelix.h.

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

double TwoTrackMinimumDistanceHelixHelix::thepH0 [private]

Definition at line 49 of file TwoTrackMinimumDistanceHelixHelix.h.

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

double TwoTrackMinimumDistanceHelixHelix::thesingjac [private]

Definition at line 60 of file TwoTrackMinimumDistanceHelixHelix.h.

Referenced by oneIteration().

double TwoTrackMinimumDistanceHelixHelix::thesinpG [mutable, private]

Definition at line 54 of file TwoTrackMinimumDistanceHelixHelix.h.

Referenced by oneIteration().

double TwoTrackMinimumDistanceHelixHelix::thesinpG0 [private]

Definition at line 47 of file TwoTrackMinimumDistanceHelixHelix.h.

Referenced by finalPoints(), and updateCoeffs().

double TwoTrackMinimumDistanceHelixHelix::thesinpH [mutable, private]

Definition at line 54 of file TwoTrackMinimumDistanceHelixHelix.h.

Referenced by oneIteration().

double TwoTrackMinimumDistanceHelixHelix::thesinpH0 [private]

Definition at line 48 of file TwoTrackMinimumDistanceHelixHelix.h.

Referenced by finalPoints(), and updateCoeffs().

double TwoTrackMinimumDistanceHelixHelix::thetanlambdaG [private]

Definition at line 46 of file TwoTrackMinimumDistanceHelixHelix.h.

Referenced by finalPoints(), and updateCoeffs().

double TwoTrackMinimumDistanceHelixHelix::thetanlambdaH [private]

Definition at line 46 of file TwoTrackMinimumDistanceHelixHelix.h.

Referenced by finalPoints(), and updateCoeffs().

The documentation for this class was generated from the following files:
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