WirePointMeasurement Class Reference

Class for measurements in wire detectors (Straw tubes and drift chambers) which can measure the coordinate along the wire. More...

#include <WirePointMeasurement.h>

Inheritance diagram for WirePointMeasurement:

Collaboration diagram for WirePointMeasurement:

Public Member Functions
	WirePointMeasurement (int nDim=8)
	WirePointMeasurement (const TVectorD &rawHitCoords, const TMatrixDSym &rawHitCov, int detId, int hitId, TrackPoint *trackPoint)
virtual AbsMeasurement *	clone () const override
	Deep copy ctor for polymorphic class.
virtual SharedPlanePtr	constructPlane (const StateOnPlane &state) const override
	Construct (virtual) detector plane (use state's AbsTrackRep). More...
virtual std::vector< MeasurementOnPlane * >	constructMeasurementsOnPlane (const StateOnPlane &state) const override
	Hits with a small drift distance get a higher weight, whereas hits with big drift distances become weighted down. More...
virtual const AbsHMatrix *	constructHMatrix (const AbsTrackRep *) const override
	Returns a new AbsHMatrix object. More...
void	setMaxDistance (double d)
	Set maximum drift distance. More...
void	setLeftRightResolution (int lr)
	select how to resolve the left/right ambiguity: -1: negative (left) side on vector (track direction) x (wire direction) 0: auto select (take side with smallest distance to track) 1: positive (right) side on vector (track direction) x (wire direction)
virtual bool	isLeftRightMeasurement () const override
	If the AbsMeasurement is a wire hit, the left/right resolution will be used.
virtual int	getLeftRightResolution () const override
double	getMaxDistance ()
TrackPoint *	getTrackPoint () const
void	setTrackPoint (TrackPoint *tp)
const TVectorD &	getRawHitCoords () const
TVectorD &	getRawHitCoords ()
const TMatrixDSym &	getRawHitCov () const
TMatrixDSym &	getRawHitCov ()
int	getDetId () const
int	getHitId () const
unsigned int	getDim () const
void	setRawHitCoords (const TVectorD &coords)
void	setRawHitCov (const TMatrixDSym &cov)
void	setDetId (int detId)
void	setHitId (int hitId)
virtual void	Print (const Option_t *="") const

Protected Attributes
double	maxDistance_
signed char	leftRight_
TVectorD	rawHitCoords_
TMatrixDSym	rawHitCov_
int	detId_
int	hitId_
TrackPoint *	trackPoint_
	Pointer to TrackPoint where the measurement belongs to.

Detailed Description

Class for measurements in wire detectors (Straw tubes and drift chambers) which can measure the coordinate along the wire.

Author

Christian Höppner (Technische Universität München, original author)

Lia Lavezzi (INFN Pavia, original author)

Sebastian Neubert (Technische Universität München, original author)

Johannes Rauch (Technische Universität München, original author)

This is not valid for any kind of plane orientation choice: to use it you MUST choose a plane described by u and v axes with v coincident with the wire (and u orthogonal to it, obviously). The hit will be described by 8 coordinates: w_x1, w_y1, w_z1, w_x2, w_y2, w_z2, rdrift, zreco where w_ji (with j = x, y, z and i = 1, 2) are the wire extremities coordinates; rdrift = distance from the wire (u coordinate in the plane) and zreco = coordinate along the wire (w2 -w1) (in the plane reference frame, v coordinate).

Definition at line 51 of file WirePointMeasurement.h.

Member Function Documentation

constructHMatrix()

const AbsHMatrix * constructHMatrix ( const AbsTrackRep *  ) const

overridevirtual

Returns a new AbsHMatrix object.

Caller must take ownership.

Reimplemented from WireMeasurement.

Definition at line 118 of file WirePointMeasurement.cc.

                                                                                     {
  if (dynamic_cast<const RKTrackRep*>(rep) == nullptr) {
    Exception exc("WirePointMeasurement default implementation can only handle state vectors of type RKTrackRep!", __LINE__,__FILE__);
    throw exc;
  }
 
  return new HMatrixUV();
}

constructMeasurementsOnPlane()

std::vector< MeasurementOnPlane * > constructMeasurementsOnPlane ( const StateOnPlane &  state ) const

overridevirtual

Hits with a small drift distance get a higher weight, whereas hits with big drift distances become weighted down.

When these initial weights are used by the DAF, the smoothed track will be closer to the real trajectory than if both sides are weighted with 0.5 regardless of the drift distance. This helps a lot when resolving l/r ambiguities with the DAF. The idea is that for the first iteration of the DAF, the wire positions are taken. For small drift radii, the wire position does not bend the fit away from the trajectory, whereas the wire position for hits with large drift radii is further away from the trajectory and will therefore bias the fit if not weighted down.

Reimplemented from WireMeasurement.

Definition at line 79 of file WirePointMeasurement.cc.

constructPlane()

SharedPlanePtr constructPlane ( const StateOnPlane &  state ) const

overridevirtual

Construct (virtual) detector plane (use state's AbsTrackRep).

It's possible to make corrections to the plane here. The state should be defined somewhere near the measurement. For virtual planes, the state will be extrapolated to the POCA to point (SpacepointMeasurement) or line (WireMeasurement), and from this info the plane will be constructed.

Reimplemented from WireMeasurement.

Definition at line 45 of file WirePointMeasurement.cc.

setMaxDistance()

void setMaxDistance ( double  d )

inlineinherited

Set maximum drift distance.

This is used to calculate the start weights of the two measurementsOnPlane.

Definition at line 81 of file WireMeasurement.h.

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

• genfit2/code2/measurements/include/WirePointMeasurement.h
• genfit2/code2/measurements/src/WirePointMeasurement.cc