Linear trajectory in sz space. More...

#include <CDCTrajectorySZ.h>

Public Member Functions
	CDCTrajectorySZ ()
	Default constructor for ROOT compatibility.

	CDCTrajectorySZ (const UncertainSZLine &szLine)
	Constructs the trajectory from the given two dimensional sz line.

	CDCTrajectorySZ (const double tanLambda, const double z0)
	Constructs the trajectory with the given slope and start z.

double	mapSToZ (const double s=0) const
	Translates the travel distance to the z coordinate.

double	mapPtToPz (const double pt) const
	Translates the absolute value of the transvers momentum to the momentum in z direction.

double	getZDist (const double s, const double z) const
	Calculates the distance along between the given point an the sz trajectory.

double	getSZDist (const double s, const double z) const
	Gets the signed distance of the sz point to the line in the sz plane This gives the signed distance of a given point in the sy plane Errors in s and z are equaly weighted in this distance ( which might be an incorrect choice to fit to ).

void	passiveMoveS (const double deltaS)
	Passively Shift the s coordinate by the amount given.

bool	isFitted () const
	Indicates if the line has been fitted.

void	clear ()
	Clears all information from this trajectory line.

double	getTanLambda () const
	Getter for the slope over the travel distance coordinate.

double	getZ0 () const
	Getter for the z coordinate at zero travel distance.

double	getPValue () const
	Getter for p-value.

double	getChi2 () const
	Getter for the chi square value of the line fit.

void	setChi2 (const double chi2)
	Setter for the chi square value of the line fit.

size_t	getNDF () const
	Getter for the number of degrees of freedom of the line fit.

void	setNDF (std::size_t ndf)
	Setter for the number of degrees of freedom of the line fit.

const UncertainSZLine &	getSZLine () const
	Getter for the line in sz space.

void	setSZLine (const UncertainSZLine &szLine)
	Setter for the line in sz space.

Static Public Member Functions
static SZCovariance	getBasicSZCovariance ()
	Getter for a default assumption about the parameter covariances.

static CDCTrajectorySZ	basicAssumption ()
	Constucts a basic assumption, what the z0 start position and the sz slope are, including some broad values for the covariance matrix.

Private Attributes
UncertainSZLine	m_szLine
	Memory for the line representation.

Detailed Description

Linear trajectory in sz space.

Particle trajectories have a linear dependence between the travel distance s and
the z coordinate as the magnetic fields along z does not disturb the free z movement.
This class presents this trajectory projection by a line representation in sz space. The s coordinate is interpreted as the transvers travel distance, hence
the part of the travel distance see in the xy projection.

Definition at line 31 of file CDCTrajectorySZ.h.

Constructor & Destructor Documentation

◆ CDCTrajectorySZ() [1/3]

CDCTrajectorySZ ( )

inline

Default constructor for ROOT compatibility.

Definition at line 39 of file CDCTrajectorySZ.h.

39{}

◆ CDCTrajectorySZ() [2/3]

CDCTrajectorySZ ( const UncertainSZLine & szLine )

inlineexplicit

Constructs the trajectory from the given two dimensional sz line.

Definition at line 42 of file CDCTrajectorySZ.h.

43 : m_szLine(szLine)

44 {}

Belle2::TrackFindingCDC::CDCTrajectorySZ::m_szLine

UncertainSZLine m_szLine

Memory for the line representation.

Definition: CDCTrajectorySZ.h:141

◆ CDCTrajectorySZ() [3/3]

CDCTrajectorySZ	(	const double	tanLambda,
		const double	z0
	)

inline

Constructs the trajectory with the given slope and start z.

Definition at line 47 of file CDCTrajectorySZ.h.

48 : m_szLine(tanLambda, z0, getBasicSZCovariance())

49 {}

Belle2::TrackFindingCDC::CDCTrajectorySZ::getBasicSZCovariance

static SZCovariance getBasicSZCovariance()

Getter for a default assumption about the parameter covariances.

Definition: CDCTrajectorySZ.cc:15

Member Function Documentation

◆ basicAssumption()

CDCTrajectorySZ basicAssumption ( )

static

Constucts a basic assumption, what the z0 start position and the sz slope are, including some broad values for the covariance matrix.

Definition at line 27 of file CDCTrajectorySZ.cc.

{
  // A dummy line with no increasing z coordinate
  double tanLambda = 0.0;
  double z0 = 0.0;
  SZCovariance szCovariance = getBasicSZCovariance();
  UncertainSZLine uncertainSZLine(tanLambda, z0, szCovariance);
  CDCTrajectorySZ trajectorySZ(uncertainSZLine);
  return trajectorySZ;
}

◆ clear()

void clear ( )

inline

Clears all information from this trajectory line.

Definition at line 100 of file CDCTrajectorySZ.h.

101 { m_szLine.invalidate(); }

Belle2::TrackFindingCDC::UncertainSZLine::invalidate

void invalidate()

Sets all line parameters to zero including the covariance matrix.

Definition: UncertainSZLine.h:158

◆ getBasicSZCovariance()

SZCovariance getBasicSZCovariance ( )

static

Getter for a default assumption about the parameter covariances.

Definition at line 15 of file CDCTrajectorySZ.cc.

{
  // Dummy error estimates
  SZCovariance szCovariance;
  using namespace NSZParameterIndices;
  szCovariance(c_TanL, c_TanL) = 2.0; // Error in pz double the error in pt, good estimate?
  szCovariance(c_Z0, c_TanL) = 0.0;
  szCovariance(c_TanL, c_Z0) = 0.0;
  szCovariance(c_Z0, c_Z0) = 2.0;
  return szCovariance;
}

◆ getChi2()

double getChi2 ( ) const

inline

Getter for the chi square value of the line fit.

Definition at line 116 of file CDCTrajectorySZ.h.

117 { return getSZLine().chi2(); }

Belle2::TrackFindingCDC::CDCTrajectorySZ::getSZLine

const UncertainSZLine & getSZLine() const

Getter for the line in sz space.

Definition: CDCTrajectorySZ.h:132

Belle2::TrackFindingCDC::UncertainSZLine::chi2

double chi2() const

Getter for the chi square value of the line fit.

Definition: UncertainSZLine.h:134

◆ getNDF()

size_t getNDF ( ) const

inline

Getter for the number of degrees of freedom of the line fit.

Definition at line 124 of file CDCTrajectorySZ.h.

125 { return getSZLine().ndf(); }

Belle2::TrackFindingCDC::UncertainSZLine::ndf

std::size_t ndf() const

Getter for the number of degrees of freediom used in the line fit.

Definition: UncertainSZLine.h:146

◆ getPValue()

double getPValue ( ) const

inline

Getter for p-value.

Definition at line 112 of file CDCTrajectorySZ.h.

113 { return TMath::Prob(getChi2(), getNDF()); }

Belle2::TrackFindingCDC::CDCTrajectorySZ::getChi2

double getChi2() const

Getter for the chi square value of the line fit.

Definition: CDCTrajectorySZ.h:116

Belle2::TrackFindingCDC::CDCTrajectorySZ::getNDF

size_t getNDF() const

Getter for the number of degrees of freedom of the line fit.

Definition: CDCTrajectorySZ.h:124

◆ getSZDist()

double getSZDist	(	const double	s,
		const double	z
	)		const

inline

Gets the signed distance of the sz point to the line in the sz plane This gives the signed distance of a given point in the sy plane
Errors in s and z are equaly weighted in this distance
( which might be an incorrect choice to fit to ).

The plus sign mean the point is below the line. For minus it is above. The later is naturally choosen as the direction of positiv advance is
coaligned with the s axes

Definition at line 80 of file CDCTrajectorySZ.h.

81 { return getSZLine()->distance(Vector2D(s, z)) ; }

Belle2::TrackFindingCDC::SZLine::distance

double distance(const Vector2D &szPoint) const

Calculates the signed distance of the point to the line.

Definition: SZLine.h:165

◆ getSZLine()

const UncertainSZLine & getSZLine ( ) const

inline

Getter for the line in sz space.

Definition at line 132 of file CDCTrajectorySZ.h.

133 { return m_szLine; }

◆ getTanLambda()

double getTanLambda ( ) const

inline

Getter for the slope over the travel distance coordinate.

Definition at line 104 of file CDCTrajectorySZ.h.

105 { return getSZLine()->slope(); }

Belle2::TrackFindingCDC::SZLine::slope

double slope() const

Getter for the slope in the sz space which is equivalent to tan lambda.

Definition: SZLine.h:58

◆ getZ0()

double getZ0 ( ) const

inline

Getter for the z coordinate at zero travel distance.

Definition at line 108 of file CDCTrajectorySZ.h.

109 { return getSZLine()->intercept(); }

Belle2::TrackFindingCDC::SZLine::intercept

double intercept() const

Getter for the intercept in the sz space which is equivalent to z0.

Definition: SZLine.h:88

◆ getZDist()

double getZDist	(	const double	s,
		const double	z
	)		const

inline

Calculates the distance along between the given point an the sz trajectory.

Definition at line 68 of file CDCTrajectorySZ.h.

69 { return mapSToZ(s) - z; }

Belle2::TrackFindingCDC::CDCTrajectorySZ::mapSToZ

double mapSToZ(const double s=0) const

Translates the travel distance to the z coordinate.

Definition: CDCTrajectorySZ.h:55

◆ isFitted()

bool isFitted ( ) const

inline

Indicates if the line has been fitted.

Definition at line 96 of file CDCTrajectorySZ.h.

97 { return not m_szLine->isInvalid(); }

Belle2::TrackFindingCDC::SZLine::isInvalid

bool isInvalid() const

Indicates if the line parameters do not represent a valid line.

Definition: SZLine.h:142

◆ mapPtToPz()

double mapPtToPz ( const double pt ) const

inline

Translates the absolute value of the transvers momentum to the momentum in z direction.

Scales the absolute value of the transvers momentum to the z component of the momentum vector. The z component comes with the correct sign as reflected by increasing or decreasing z component. Note : This assumes s to be the transvers travel distance.

Definition at line 64 of file CDCTrajectorySZ.h.

65 { return getSZLine()->slope() * pt; }

◆ mapSToZ()

double mapSToZ ( const double s = 0 ) const

inline

Translates the travel distance to the z coordinate.

Definition at line 55 of file CDCTrajectorySZ.h.

56 { return getSZLine()->map(s); }

Belle2::TrackFindingCDC::SZLine::map

double map(double s) const

Maps the two dimensional arc length s to z.

Definition: SZLine.h:116

◆ passiveMoveS()

void passiveMoveS ( const double deltaS )

inline

Passively Shift the s coordinate by the amount given.

Adjust all transvers travel distance measurements by deltaS.
The old values of s before the shift corresponds the new scale
like old_s - deltaS = new_s. This corresponds to an passive transformation
of s by deltaS. This can be used in conjunction with the return value of
CDCTrajectory2D::setStartPos2D() in order to move the transvers travel distance
by the same amount in both trajectories.

Definition at line 92 of file CDCTrajectorySZ.h.

93 { m_szLine.passiveMoveBy(Vector2D(deltaS, 0)); }

Belle2::TrackFindingCDC::UncertainSZLine::passiveMoveBy

void passiveMoveBy(const Vector2D &bySZ)

Moves the coordinate system by the vector by and calculates the new sz line and its covariance matrix...

Definition: UncertainSZLine.h:183

◆ setChi2()

void setChi2 ( const double chi2 )

inline

Setter for the chi square value of the line fit.

Definition at line 120 of file CDCTrajectorySZ.h.

121 { return m_szLine.setChi2(chi2); }

Belle2::TrackFindingCDC::UncertainSZLine::setChi2

void setChi2(const double chi2)

Setter for the chi square value of the line fit.

Definition: UncertainSZLine.h:140

◆ setNDF()

void setNDF ( std::size_t ndf )

inline

Setter for the number of degrees of freedom of the line fit.

Definition at line 128 of file CDCTrajectorySZ.h.

129 { return m_szLine.setNDF(ndf); }

Belle2::TrackFindingCDC::UncertainSZLine::setNDF

void setNDF(std::size_t ndf)

Setter for the number of degrees of freediom used in the line fit.

Definition: UncertainSZLine.h:152

◆ setSZLine()

void setSZLine ( const UncertainSZLine & szLine )

inline

Setter for the line in sz space.

Definition at line 136 of file CDCTrajectorySZ.h.

137 { m_szLine = szLine; }

Member Data Documentation

◆ m_szLine

UncertainSZLine m_szLine

private

Memory for the line representation.

Definition at line 141 of file CDCTrajectorySZ.h.

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

tracking/trackFindingCDC/eventdata/trajectories/include/CDCTrajectorySZ.h
tracking/trackFindingCDC/eventdata/trajectories/src/CDCTrajectorySZ.cc

Public Member Functions

Static Public Member Functions

Private Attributes

Detailed Description

Constructor & Destructor Documentation

◆ CDCTrajectorySZ() [1/3]

◆ CDCTrajectorySZ() [2/3]

◆ CDCTrajectorySZ() [3/3]

Member Function Documentation

◆ basicAssumption()

◆ clear()

◆ getBasicSZCovariance()

◆ getChi2()

◆ getNDF()

◆ getPValue()

◆ getSZDist()

◆ getSZLine()

◆ getTanLambda()

◆ getZ0()

◆ getZDist()

◆ isFitted()

◆ mapPtToPz()

◆ mapSToZ()

◆ passiveMoveS()

◆ setChi2()

◆ setNDF()

◆ setSZLine()

Member Data Documentation

◆ m_szLine