geometry

Collaboration diagram for geometry:

Modules
	geometry data objects
	geometry modules

Namespaces
	Belle2::geometry
	Common code concerning the geometry representation of the detector.

Classes
class	BFieldComponent3d
	The BFieldComponent3d class. More...
class	BFieldComponentAbs
	The BFieldComponentAbs class. More...
class	BFieldComponentBeamline
	The BFieldComponentBeamline class. More...
class	BFieldComponentConstant
	The BFieldComponentConstant class. More...
class	BFieldComponentKlm1
	The Bfieldcomponentklm1 class. More...
class	BFieldComponentQuad
	The BFieldComponentQuad class. More...
class	BFieldComponentRadial
	The BFieldComponentRadial class. More...
class	BFieldFrameworkInterface
	Simple BFieldComponent to just wrap the existing BFieldMap with the new BFieldManager. More...
class	BFieldMap
	This class represents the magnetic field of the Belle II detector. More...
class	GeoMagneticField
	The GeoMagneticField class. More...
struct	triangle_t
	Triangle structure. More...
struct	xy_t
	A simple 2d vector stucture. More...
class	TriangularInterpolation
	The TriangularInterpolation class. More...
class	BeamlineFieldMapInterpolation
	The BeamlineFieldMapInterpolation class. More...
class	GeoComponent
	Describe one component of the Geometry. More...
class	GeoConfiguration
	configuration of the geometry More...
class	GeoMaterial
	Class to represent a material informaion in the Database. More...
class	GeoMaterialComponent
	Component of a material. More...
class	GeoMaterialProperty
	Property of a material. More...
class	GeoOpticalSurface
	Represent an optical finish of a surface. More...
class	MagneticFieldComponent3D
	Describe one component of the Geometry. More...
class	MyDBPayloadClass
	Class containing all the parameters needed to create the geometry and suitable to save into a ROOT file to be used from the Database. More...
class	MyDBCreator
	Very simple Creator class which actually does not do anything but shows how creators should implement loading the geometry from database. More...

Functions
BFieldComponentBeamline **	GetInstancePtr ()
	Static function holding the instance.
BFieldComponentRadial::BFieldPoint	operator* (const BFieldComponentRadial::BFieldPoint &v, double a)
	multiply a radial bfield point by a real number
BFieldComponentRadial::BFieldPoint	operator+ (const BFieldComponentRadial::BFieldPoint &u, const BFieldComponentRadial::BFieldPoint &v)
	Add two radial bfield points together.
template<class BFIELDCOMP >
BFIELDCOMP &	addBFieldComponent ()
	Adds a new BField component to the Belle II magnetic field. More...
B2Vector3D	getBField (const B2Vector3D &point) const
	Returns the magnetic field of the Belle II detector at the specified space point. More...
virtual void	initialize () override
	Initializes the magnetic field component. More...
virtual	~BFieldComponentBeamline ()
	The BFieldComponentBeamline destructor.
bool	isInRange (const B2Vector3D &point) const
	Check presence of beamline field at the specific space point in the detector coordinate frame. More...
virtual B2Vector3D	calculate (const B2Vector3D &point) const override
	Calculates the magnetic field vector at the specified space point. More...
virtual void	terminate () override
	Terminates the magnetic field component. More...
static BFieldComponentBeamline &	Instance ()
	BFieldComponentBeamline instance. More...
	BFieldComponentBeamline ()
	The BFieldComponentBeamline constructor.
B2Vector3D	getField (const B2Vector3D &pos) const override
	return the field assuming we are inside the active region as returned by inside() More...
B2Vector3D	interpolate (unsigned int ir, unsigned int iphi, unsigned int iz, double wr, double wphi, double wz) const
	Linear interpolate the magnetic field inside a bin. More...

Detailed Description

Function Documentation

addBFieldComponent()

BFIELDCOMP & addBFieldComponent

Adds a new BField component to the Belle II magnetic field.

The class of the magnetic field component has to inherit from BFieldComponentAbs.

Returns

A reference to the added magnetic field component.

Definition at line 109 of file BFieldMap.h.

  {
    B2Vector3D magFieldVec(0.0, 0.0, 0.0);
    //Check that the point makes sense
    if (std::isnan(point.X()) || std::isnan(point.Y()) || std::isnan(point.Z())) {
      B2ERROR("Bfield requested for a position containing NaN, returning field 0");

calculate()

B2Vector3D calculate ( const B2Vector3D &  point ) const

overridevirtual

Calculates the magnetic field vector at the specified space point.

Parameters

point

The space point in Cartesian coordinates (x,y,z) in [cm] at which the magnetic field vector should be calculated.

Returns

The magnetic field vector at the given space point in [T]. Returns a zero vector TVector(0,0,0) if the space point lies outside the region described by the component.

Implements BFieldComponentAbs.

Definition at line 663 of file BFieldComponentBeamline.cc.

  {
    B2Vector3D res;
    double s = m_sinBeamCrossAngle, c = m_cosBeamCrossAngle;
    B2Vector3D v = -p; // invert coordinates to match ANSYS one
    double xc = v.x() * c, zs = v.z() * s, zc = v.z() * c, xs = v.x() * s;
    B2Vector3D hv{xc - zs, v.y(), zc + xs};
    B2Vector3D lv{xc + zs, v.y(), zc - xs};
    B2Vector3D hb = m_her->interpolateField(hv);
    B2Vector3D lb = m_ler->interpolateField(lv);
    B2Vector3D rhb{hb.x()* c + hb.z()* s, hb.y(),  hb.z()* c - hb.x()* s};
    B2Vector3D rlb{lb.x()* c - lb.z()* s, lb.y(),  lb.z()* c + lb.x()* s};
 
    double mhb = std::abs(rhb.x()) + std::abs(rhb.y()) + std::abs(rhb.z());
    double mlb = std::abs(rlb.x()) + std::abs(rlb.y()) + std::abs(rlb.z());
 
    if (mhb < 1e-10) res = rlb;
    else if (mlb < 1e-10) res = rhb;
    else {
      res = 0.5 * (rlb + rhb);
    }
    return res;
  }

getBField()

B2Vector3D getBField ( const B2Vector3D &  point ) const

inlineprivate

Returns the magnetic field of the Belle II detector at the specified space point.

The space point is given in Cartesian coordinates (x,y,z) in [cm].

Parameters

point

The space point in Cartesian coordinates.

Returns

A three vector of the magnetic field in [T] at the specified space point.

Definition at line 117 of file BFieldMap.h.

getField()

B2Vector3D getField ( const B2Vector3D &  pos ) const

overridevirtual

return the field assuming we are inside the active region as returned by inside()

small helper function to calculate the bin index and fraction inside the index given a relative coordinate and the coordinate index (0=R, 1=Phi, 2=Z).

Example: If the z grid starts at 5 and goes to 15 with 6 points (pitch size of 2), then calling getIndexWeight(10.5, 2) will return tuple(2, 0.75) since the 10.5 lies in bin "2" and is already 75% to the next bin

It will also cap the index to be inside the valid grid range

Returns a tuple with the bin index as first element and the weight fraction inside the bin as second element

Implements MagneticFieldComponent.

Definition at line 91 of file MagneticFieldComponent3D.cc.

  {
    using std::get;
 
    auto getIndexWeight = [this](double value, int coordinate) -> std::tuple<unsigned int, double> {
      double weight = value * m_invgridPitch[coordinate];
      auto index = static_cast<unsigned int>(weight);
      index = std::min(index, static_cast<unsigned int>(m_mapSize[coordinate] - 2));
      weight -= index;
      return std::make_tuple(index, weight);
    };
 
    const double z = pos.z();
    const double r2 = pos.Perp2();
 
    // Calculate the lower index of the point in the Z grid
    // Note that z coordinate is inverted to match ANSYS frame
    const auto iz = getIndexWeight(m_maxZ - z, 2);
 
    // directly on z axis: get B-field values from map in cartesian system assuming phi=0, so Bx = Br and By = Bphi
    if (r2 == 0) return interpolate(0, 0, get<0>(iz), 0, 0, get<1>(iz));
 
    const double r = std::sqrt(r2);
    const auto ir = getIndexWeight(r - m_minR, 0);
 
    // Calculate the lower index of the point in the Phi grid
    const double ay = std::abs(pos.y());
    const auto iphi = getIndexWeight(fast_atan2_minimax<4>(ay, pos.x()), 1);
 
    // Get B-field values from map in cylindrical coordinates
    B2Vector3D b = interpolate(get<0>(ir), get<0>(iphi), get<0>(iz), get<1>(ir), get<1>(iphi), get<1>(iz));
    // and convert it to cartesian
    const double norm = 1 / r;
    const double s = ay * norm;
    const double c = pos.x() * norm;
    // Flip sign of By if y<0
    const double sgny = (pos.y() >= 0) - (pos.y() < 0);
    // in cartesian system
    return B2Vector3D(-(b.x() * c - b.y() * s), -sgny * (b.x() * s + b.y() * c), b.z());
  }

initialize()

void initialize ( )

overridevirtual

Initializes the magnetic field component.

This method opens the magnetic field map file.

Reimplemented from BFieldComponentAbs.

Definition at line 638 of file BFieldComponentBeamline.cc.

Instance()

BFieldComponentBeamline & Instance ( )

static

BFieldComponentBeamline instance.

static function

Returns

reference to the BFieldComponentBeamline instance

Definition at line 699 of file BFieldComponentBeamline.cc.

interpolate()

B2Vector3D interpolate ( unsigned int  ir, unsigned int  iphi, unsigned int  iz, double  wr, double  wphi, double  wz  ) const

private

Linear interpolate the magnetic field inside a bin.

Parameters

ir	number of the bin in r
iphi	number of the bin in phi
iz	number of the bin in z
wr	r weight: fraction we are away from the lower r corner relative to the pitch size
wphi	phi weight: fraction we are away from the lower phi corner relative to the pitch size
wz	phi weight: fraction we are away from the lower z corner relative to the pitch size

Definition at line 145 of file MagneticFieldComponent3D.cc.

isInRange()

bool isInRange

(

const B2Vector3D &

point

)

const

Check presence of beamline field at the specific space point in the detector coordinate frame.

Parameters

point

The space point in Cartesian coordinates (x,y,z) in [cm] at which the magnetic field presence is chcked

Returns

true is in case of the magnetic field false – otherwise

Definition at line 652 of file BFieldComponentBeamline.cc.

terminate()

void terminate ( )

overridevirtual

Terminates the magnetic field component.

This method closes the magnetic field map file.

Reimplemented from BFieldComponentAbs.

Definition at line 687 of file BFieldComponentBeamline.cc.