Belle II Software  release-08-01-10
WireMeasurementNew Class Reference

Class for measurements in wire detectors (Straw tubes and drift chambers) which do not measure the coordinate along the wire. More...

#include <WireMeasurementNew.h>

Inheritance diagram for WireMeasurementNew:
Collaboration diagram for WireMeasurementNew:

Public Member Functions

 WireMeasurementNew (double driftDistance, double driftDistanceError, const TVector3 &endPoint1, const TVector3 &endPoint2, int detId, int hitId, TrackPoint *trackPoint)
 
virtual WireMeasurementNewclone () 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 AbsHMatrixconstructHMatrix (const AbsTrackRep *) const override
 Returns a new AbsHMatrix object. More...
 
void setWireEndPoints (const TVector3 &endPoint1, const TVector3 &endPoint2)
 Reset the wire end points.
 
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 (wire direction) x (track direction) 0: mirrors enter with same weight, DAF will decide. More...
 
virtual bool isLeftRigthMeasurement () const
 
double getMaxDistance ()
 
int getLeftRightResolution () const override
 
TrackPointgetTrackPoint () const
 
void setTrackPoint (TrackPoint *tp)
 
const TVectorD & getRawHitCoords () const
 
TVectorD & getRawHitCoords ()
 
const TMatrixDSym & getRawHitCov () const
 
TMatrixDSym & getRawHitCov ()
 
int getDetId () const
 
int getHitId () const
 
virtual bool isLeftRightMeasurement () const
 If the AbsMeasurement is a wire hit, the left/right resolution will be used.
 
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 wireEndPoint1_ [3]
 
double wireEndPoint2_ [3]
 Wire end point 1 (X, Y, Z)
 
double maxDistance_
 Wire end point 2 (X, Y, Z)
 
double leftRight_
 
TVectorD rawHitCoords_
 
TMatrixDSym rawHitCov_
 
int detId_
 
int hitId_
 
TrackPointtrackPoint_
 Pointer to TrackPoint where the measurement belongs to.
 

Detailed Description

Class for measurements in wire detectors (Straw tubes and drift chambers) which do not measure the coordinate along the wire.

Author
Tobias Schlüter

This is similar to WireMeasurement, but since WireMeasurement stores a 7x7 covariance matrix for what is a one-dimensional measurement, this class is preferable. Protected inheritance of rawHitCoords_ and rawHitCov_ makes it impossible to rewrite WireMeasurement, as subclasses will access these members.

This hit class is not valid for arbitrary choices of plane orientation: 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 7 coordinates: w_x1, w_y1, w_z1, w_x2, w_y2, w_z2, rdrift 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)

Definition at line 56 of file WireMeasurementNew.h.

Member Function Documentation

◆ constructHMatrix()

const AbsHMatrix * constructHMatrix ( const AbsTrackRep ) const
overridevirtual

Returns a new AbsHMatrix object.

Caller must take ownership.

Implements AbsMeasurement.

Definition at line 132 of file WireMeasurementNew.cc.

132  {
133  if (dynamic_cast<const RKTrackRep*>(rep) == nullptr) {
134  Exception exc("WireMeasurementNew default implementation can only handle state vectors of type RKTrackRep!", __LINE__,__FILE__);
135  throw exc;
136  }
137 
138  return new HMatrixU();
139 }

◆ 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.

Implements AbsMeasurement.

Definition at line 98 of file WireMeasurementNew.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.

Implements AbsMeasurement.

Definition at line 64 of file WireMeasurementNew.cc.

◆ setLeftRightResolution()

void setLeftRightResolution ( int  lr)

select how to resolve the left/right ambiguity: -1: negative (left) side on vector (wire direction) x (track direction) 0: mirrors enter with same weight, DAF will decide.

1: positive (right) side on vector (wire direction) x (track direction) where the wire direction is pointing from endPoint1 to endPoint2

Definition at line 152 of file WireMeasurementNew.cc.

◆ setMaxDistance()

void setMaxDistance ( double  d)
inline

Set maximum drift distance.

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

Definition at line 89 of file WireMeasurementNew.h.

89 {maxDistance_ = d;}
double maxDistance_
Wire end point 2 (X, Y, Z)

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