ShipBFieldMap Class Reference

Class that defines a (3d) magnetic field map (distances in cm, fields in tesla) More...

#include <ShipBFieldMap.h>

Inheritance diagram for ShipBFieldMap:

Collaboration diagram for ShipBFieldMap:

Public Types
typedef std::vector< std::vector< Float_t > >	floatArray
	Typedef for a vector containing a vector of floats.

Public Member Functions
	ShipBFieldMap (const std::string &label, const std::string &mapFileName, Float_t xOffset=0.0, Float_t yOffset=0.0, Float_t zOffset=0.0, Float_t phi=0.0, Float_t theta=0.0, Float_t psi=0.0, Float_t scale=1.0, Bool_t isSymmetric=kFALSE)
	Constructor.
	ShipBFieldMap (const std::string &newName, const ShipBFieldMap &rhs, Float_t newXOffset, Float_t newYOffset, Float_t newZOffset, Float_t newPhi=0.0, Float_t newTheta=0.0, Float_t newPsi=0.0, Float_t newScale=1.0)
virtual	~ShipBFieldMap ()
	Destructor.
virtual void	Field (const Double_t *position, Double_t *B)
	Implementation of evaluating the B field.
floatArray *	getFieldMap () const
	Retrieve the field map.
void	SetXOffset (Float_t xValue)
	Set the x global coordinate shift.
void	SetYOffset (Float_t yValue)
	Set the y global coordinate shift.
void	SetZOffset (Float_t zValue)
	Set the z global coordinate shift.
void	SetPhi (Float_t phi)
	Set the first Euler rotation angle phi about the z axis.
void	SetTheta (Float_t theta)
	Set the second Euler rotation angle theta about the new x axis.
void	SetPsi (Float_t psi)
	Set the third Euler rotation angle psi about the new z axis.
void	SetScale (Float_t scale)
	Set the field magnitude scaling factor.
void	UseSymmetry (Bool_t flag)
	Set the boolean to specify if we have quadrant symmetry.
std::string	GetMapFileName () const
	Get the name of the map file.
Int_t	GetNx () const
	Get the number of bins along x.
Int_t	GetNy () const
	Get the number of bins along y.
Int_t	GetNz () const
	Get the number of bins along z.
Int_t	GetNBins () const
	Get the total number of bins.
Float_t	GetXMin () const
	Get the minimum value of x for the map.
Float_t	GetXMax () const
	Get the maximum value of x for the map.
Float_t	GetdX () const
	Get the bin width along x for the map.
Float_t	GetXRange () const
	Get the x coordinate range for the map.
Float_t	GetYMin () const
	Get the minimum value of y for the map.
Float_t	GetYMax () const
	Get the maximum value of y for the map.
Float_t	GetdY () const
	Get the bin width along y for the map.
Float_t	GetYRange () const
	Get the y coordinate range for the map.
Float_t	GetZMin () const
	Get the minimum value of z for the map.
Float_t	GetZMax () const
	Get the maximum value of z for the map.
Float_t	GetdZ () const
	Get the bin width along z for the map.
Float_t	GetZRange () const
	Get the z coordinate range for the map.
Float_t	GetXOffset () const
	Get the x offset coordinate of the map for global positioning.
Float_t	GetYOffset () const
	Get the y offset coordinate of the map for global positioning.
Float_t	GetZOffset () const
	Get the z offset coordinate of the map for global positioning.
Float_t	GetPhi () const
	Get the first Euler rotation angle about the z axis for global positioning.
Float_t	GetTheta () const
Float_t	GetPsi () const
Float_t	GetScale () const
	Get the field magnitude scaling factor.
Bool_t	HasSymmetry () const
	Get the boolean flag to specify if we have quadrant symmetry.
Bool_t	IsACopy () const
	Get the boolean flag to specify if we are a "copy".
	ClassDef (ShipBFieldMap, 1)
	ClassDef for ROOT.

Private Types
enum	CoordAxis { xAxis = 0 , yAxis , zAxis }
	Enumeration to specify the coordinate type. More...
typedef std::pair< Int_t, Float_t >	binPair
	Typedef for an int-double pair.

Private Member Functions
	ShipBFieldMap (const ShipBFieldMap &rhs)=delete
ShipBFieldMap &	operator= (const ShipBFieldMap &rhs)=delete
void	initialise ()
	Initialisation.
void	readMapFile ()
	Read the field map data and store the information internally.
void	readRootFile ()
	Process the ROOT file containing the field map data.
void	readTextFile ()
	Process the text file containing the field map data.
void	setLimits ()
Bool_t	insideRange (Float_t x, Float_t y, Float_t z)
	Check to see if a point is within the map validity range.
binPair	getBinInfo (Float_t x, CoordAxis theAxis)
	Get the bin number and fractional distance from the leftmost bin edge.
Int_t	getMapBin (Int_t iX, Int_t iY, Int_t iZ)
	Find the vector entry of the field map data given the bins iX, iY and iZ.
Float_t	BInterCalc (CoordAxis theAxis)

Private Attributes
floatArray *	fieldMap_
std::string	mapFileName_
	The name of the map file.
Bool_t	initialised_
	Initialisation boolean.
Bool_t	isCopy_
Int_t	Nx_
	The number of bins along x.
Int_t	Ny_
	The number of bins along y.
Int_t	Nz_
	The number of bins along z.
Int_t	N_
	The total number of bins.
Float_t	xMin_
	The minimum value of x for the map.
Float_t	xMax_
	The maximum value of x for the map.
Float_t	dx_
	The bin width along x.
Float_t	xRange_
	The coordinate range along x.
Float_t	yMin_
	The minimum value of y for the map.
Float_t	yMax_
	The maximum value of y for the map.
Float_t	dy_
	The bin width along y.
Float_t	yRange_
	The coordinate range along y.
Float_t	zMin_
	The minimum value of z for the map.
Float_t	zMax_
	The maximum value of z for the map.
Float_t	dz_
	The bin width along z.
Float_t	zRange_
	The coordinate range along z.
Float_t	xOffset_
	The x value of the positional offset for the map.
Float_t	yOffset_
	The y value of the positional offset for the map.
Float_t	zOffset_
	The z value of the positional offset for the map.
Float_t	phi_
	The first Euler rotation angle about the z axis.
Float_t	theta_
	The second Euler rotation angle about the new x axis.
Float_t	psi_
	The third Euler rotation angle about the new z axis.
Float_t	scale_
	The B field magnitude scaling factor.
Bool_t	isSymmetric_
	The boolean specifying if we have quadrant symmetry.
TGeoMatrix *	theTrans_
	The combined translation and rotation transformation.
Float_t	Tesla_
	Double converting Tesla to kiloGauss (for VMC/FairRoot B field units)
Int_t	binA_
	Bin A for the trilinear interpolation.
Int_t	binB_
	Bin B for the trilinear interpolation.
Int_t	binC_
	Bin C for the trilinear interpolation.
Int_t	binD_
	Bin D for the trilinear interpolation.
Int_t	binE_
	Bin E for the trilinear interpolation.
Int_t	binF_
	Bin F for the trilinear interpolation.
Int_t	binG_
	Bin G for the trilinear interpolation.
Int_t	binH_
	Bin H for the trilinear interpolation.
Float_t	xFrac_
	Fractional bin distance along x.
Float_t	yFrac_
	Fractional bin distance along y.
Float_t	zFrac_
	Fractional bin distance along z.
Float_t	xFrac1_
	Complimentary fractional bin distance along x.
Float_t	yFrac1_
	Complimentary fractional bin distance along y.
Float_t	zFrac1_
	Complimentary fractional bin distance along z.

Detailed Description

Class that defines a (3d) magnetic field map (distances in cm, fields in tesla)

Class that defines a (3d) magnetic field map.

Author

John Back J.J.B.nosp@m.ack@.nosp@m.warwi.nosp@m.ck.a.nosp@m.c.uk

John Back J.J.B.nosp@m.ack@.nosp@m.warwi.nosp@m.ck.a.nosp@m.c.uk

Definition at line 20 of file ShipBFieldMap.h.

Member Typedef Documentation

binPair

typedef std::pair<Int_t, Float_t> ShipBFieldMap::binPair

private

Typedef for an int-double pair.

Definition at line 336 of file ShipBFieldMap.h.

floatArray

typedef std::vector<std::vector<Float_t> > ShipBFieldMap::floatArray

Typedef for a vector containing a vector of floats.

Definition at line 83 of file ShipBFieldMap.h.

Member Enumeration Documentation

CoordAxis

enum ShipBFieldMap::CoordAxis

private

Enumeration to specify the coordinate type.

Enumerator
xAxis
yAxis
zAxis

Definition at line 309 of file ShipBFieldMap.h.

{ xAxis = 0, yAxis, zAxis };

Constructor & Destructor Documentation

ShipBFieldMap() [1/3]

ShipBFieldMap::ShipBFieldMap	(	const std::string &	label,
		const std::string &	mapFileName,
		Float_t	xOffset = 0.0,
		Float_t	yOffset = 0.0,
		Float_t	zOffset = 0.0,
		Float_t	phi = 0.0,
		Float_t	theta = 0.0,
		Float_t	psi = 0.0,
		Float_t	scale = 1.0,
		Bool_t	isSymmetric = kFALSE
	)

Constructor.

for FairLogger, MESSAGE_ORIGIN

Parameters

[in]	label	A descriptive name/title/label for this field
[in]	mapFileName	The name of the field map file (distances in cm, fields in Tesla)
[in]	xOffset	The x global coordinate shift to position the field map (cm)
[in]	yOffset	The y global coordinate shift to position the field map (cm)
[in]	zOffset	The z global coordinate shift to position the field map (cm)
[in]	phi	The first Euler rotation angle about the z axis (degrees)
[in]	theta	The second Euler rotation angle about the new x axis (degrees)
[in]	psi	The third Euler rotation angle about the new z axis (degrees)
[in]	scale	The field magnitude scaling factor (default = 1.0)
[in]	isSymmetric	Boolean to specify if we have quadrant symmetry (default = false)

Definition at line 21 of file ShipBFieldMap.cxx.

    : TVirtualMagField(label.c_str()),
      fieldMap_(new floatArray()),
      mapFileName_(mapFileName),
      initialised_(kFALSE),
      isCopy_(kFALSE),
      Nx_(0),
      Ny_(0),
      Nz_(0),
      N_(0),
      xMin_(0.0),
      xMax_(0.0),
      dx_(0.0),
      xRange_(0.0),
      yMin_(0.0),
      yMax_(0.0),
      dy_(0.0),
      yRange_(0.0),
      zMin_(0.0),
      zMax_(0.0),
      dz_(0.0),
      zRange_(0.0),
      xOffset_(xOffset),
      yOffset_(yOffset),
      zOffset_(zOffset),
      phi_(phi),
      theta_(theta),
      psi_(psi),
      scale_(scale),
      isSymmetric_(isSymmetric),
      theTrans_(nullptr),
      Tesla_(10.0) {
  this->initialise();
}

ShipBFieldMap() [2/3]

ShipBFieldMap::ShipBFieldMap	(	const std::string &	newName,
		const ShipBFieldMap &	rhs,
		Float_t	newXOffset,
		Float_t	newYOffset,
		Float_t	newZOffset,
		Float_t	newPhi = 0.0,
		Float_t	newTheta = 0.0,
		Float_t	newPsi = 0.0,
		Float_t	newScale = 1.0
	)

Copy constructor with a new global transformation. Use this if you want to reuse the same field map information elsewhere in the geometry

Parameters

[in]	rhs	The ShipBFieldMap object to be copied (retaining any symmetry)
[in]	newName	The new description or title of the field
[in]	newXOffset	The new global offset x coordinate (cm)
[in]	newYOffset	The new global offset y coordinate (cm)
[in]	newZOffset	The new global offset z coordinate (cm)
[in]	newPhi	The first Euler rotation angle about the z axis (degrees)
[in]	newTheta	The second Euler rotation angle about the new x axis (degrees)
[in]	newPsi	The third Euler rotation angle about the new z axis (degrees)
[in]	newScale	The field magnitude scaling factor (default = 1.0)

Returns

a copy of the field map object "rhs", keeping the same fieldMap pointer

Definition at line 73 of file ShipBFieldMap.cxx.

    : TVirtualMagField(newName.c_str()),
      fieldMap_(rhs.fieldMap_),
      mapFileName_(rhs.GetMapFileName()),
      initialised_(kFALSE),
      isCopy_(kTRUE),
      Nx_(rhs.Nx_),
      Ny_(rhs.Ny_),
      Nz_(rhs.Nz_),
      N_(rhs.N_),
      xMin_(rhs.xMin_),
      xMax_(rhs.xMax_),
      dx_(rhs.dx_),
      xRange_(rhs.xRange_),
      yMin_(rhs.yMin_),
      yMax_(rhs.yMax_),
      dy_(rhs.dy_),
      yRange_(rhs.yRange_),
      zMin_(rhs.zMin_),
      zMax_(rhs.zMax_),
      dz_(rhs.dz_),
      zRange_(rhs.zRange_),
      xOffset_(newXOffset),
      yOffset_(newYOffset),
      zOffset_(newZOffset),
      phi_(newPhi),
      theta_(newTheta),
      psi_(newPsi),
      scale_(newScale),
      isSymmetric_(rhs.isSymmetric_),
      theTrans_(nullptr),
      Tesla_(10.0) {
  // Copy constructor with new label and different global offset, which uses
  // the same field map data (pointer) and distance units as the rhs object
  this->initialise();
}

~ShipBFieldMap()

ShipBFieldMap::~ShipBFieldMap ( )

virtual

Destructor.

Definition at line 60 of file ShipBFieldMap.cxx.

                              {
  // Delete the internal vector storing the field map values
  if (fieldMap_ && isCopy_ == kFALSE) {
    delete fieldMap_;
    fieldMap_ = nullptr;
  }
 
  if (theTrans_) {
    delete theTrans_;
    theTrans_ = nullptr;
  }
}

ShipBFieldMap() [3/3]

ShipBFieldMap::ShipBFieldMap ( const ShipBFieldMap &  rhs )

privatedelete

Member Function Documentation

BInterCalc()

Float_t ShipBFieldMap::BInterCalc ( CoordAxis  theAxis )

private

Calculate the magnetic field component using trilinear interpolation. This function uses the various "binX" integers and "uFrac" variables

Parameters

[in]

theAxis

The coordinate axis (CoordAxis enumeration for x, y or z)

Returns

the magnetic field component for the given axis

Definition at line 481 of file ShipBFieldMap.cxx.

                                                   {
  // Find the magnetic field component along theAxis using trilinear
  // interpolation based on the current position and neighbouring bins
  Float_t result(0.0);
 
  Int_t iAxis(0);
 
  if (theAxis == CoordAxis::yAxis) {
    iAxis = 1;
  } else if (theAxis == CoordAxis::zAxis) {
    iAxis = 2;
  }
 
  if (fieldMap_) {
    // Get the field component values for the neighbouring bins
    Float_t A = (*fieldMap_)[binA_][iAxis];
    Float_t B = (*fieldMap_)[binB_][iAxis];
    Float_t C = (*fieldMap_)[binC_][iAxis];
    Float_t D = (*fieldMap_)[binD_][iAxis];
    Float_t E = (*fieldMap_)[binE_][iAxis];
    Float_t F = (*fieldMap_)[binF_][iAxis];
    Float_t G = (*fieldMap_)[binG_][iAxis];
    Float_t H = (*fieldMap_)[binH_][iAxis];
 
    // Perform linear interpolation along x
    Float_t F00 = A * xFrac1_ + B * xFrac_;
    Float_t F10 = C * xFrac1_ + D * xFrac_;
    Float_t F01 = E * xFrac1_ + F * xFrac_;
    Float_t F11 = G * xFrac1_ + H * xFrac_;
 
    // Linear interpolation along y
    Float_t F0 = F00 * yFrac1_ + F10 * yFrac_;
    Float_t F1 = F01 * yFrac1_ + F11 * yFrac_;
 
    // Linear interpolation along z
    result = F0 * zFrac1_ + F1 * zFrac_;
  }
 
  return result;
}

ClassDef()

ShipBFieldMap::ClassDef	(	ShipBFieldMap	,
		1
	)

ClassDef for ROOT.

Field()

void ShipBFieldMap::Field ( const Double_t *  position, Double_t *  B  )

virtual

Implementation of evaluating the B field.

Parameters

[in]	position	The x,y,z global coordinates of the point (cm)
[out]	B	The x,y,z components of the magnetic field (kGauss = 0.1 tesla)

Definition at line 114 of file ShipBFieldMap.cxx.

                                                               {
  // Set the B field components given the global position coordinates
 
  // Convert the global position into a local one for the volume field.
  // Initialise the local co-ords, which will get overwritten if the
  // coordinate transformation exists. For a global field, any local
  // volume transformation is ignored
  Double_t localCoords[3] = {position[0], position[1], position[2]};
 
  if (theTrans_) {
    theTrans_->MasterToLocal(position, localCoords);
  }
 
  // The local position coordinates
  Float_t x = localCoords[0];
  Float_t y = localCoords[1];
  Float_t z = localCoords[2];
 
  // Now check to see if we have x-y quadrant symmetry (z has no symmetry):
  // Bx is antisymmetric in x and y, By is symmetric and Bz has no symmetry
  // so only Bx can change sign. This can happen if either x < 0 or y < 0:
  // 1. x > 0, y > 0: Bx = Bx
  // 2. x > 0, y < 0: Bx = -Bx
  // 3. x < 0, y > 0: Bx = -Bx
  // 4. x < 0, y < 0: Bx = Bx
 
  Float_t BxSign(1.0);
  Float_t BzSign = 1;
 
  if (isSymmetric_) {
    // The field map coordinates only contain x > 0 and y > 0, i.e. we
    // are using x-y quadrant symmetry. If the local x or y coordinates
    // are negative we need to change their sign and keep track of the
    // adjusted sign of Bx which we use as a multiplication factor at the end
    if (x < 0.0) {
      x = -x;
      BxSign *= -1.0;
    }
 
    if (y < 0.0) {
      y = -y;
      BxSign *= -1.0;
      BzSign = -1.0;
    }
  }
 
  // Initialise the B field components to zero
  B[0] = 0.0;
  B[1] = 0.0;
  B[2] = 0.0;
 
  // First check to see if we are inside the field map range
  Bool_t inside = this->insideRange(x, y, z);
  if (inside == kFALSE) {
    return;
  }
 
  // Find the neighbouring bins for the given point
  binPair xBinInfo = this->getBinInfo(x, ShipBFieldMap::xAxis);
  binPair yBinInfo = this->getBinInfo(y, ShipBFieldMap::yAxis);
  binPair zBinInfo = this->getBinInfo(z, ShipBFieldMap::zAxis);
 
  Int_t iX = xBinInfo.first;
  Int_t iY = yBinInfo.first;
  Int_t iZ = zBinInfo.first;
 
  // Check that the bins are valid
  if (iX == -1 || iY == -1 || iZ == -1) {
    return;
  }
 
  // Get the various neighbouring bin entries
  Int_t iX1(iX + 1);
  Int_t iY1(iY + 1);
  Int_t iZ1(iZ + 1);
 
  binA_ = this->getMapBin(iX, iY, iZ);
  binB_ = this->getMapBin(iX1, iY, iZ);
  binC_ = this->getMapBin(iX, iY1, iZ);
  binD_ = this->getMapBin(iX1, iY1, iZ);
  binE_ = this->getMapBin(iX, iY, iZ1);
  binF_ = this->getMapBin(iX1, iY, iZ1);
  binG_ = this->getMapBin(iX, iY1, iZ1);
  binH_ = this->getMapBin(iX1, iY1, iZ1);
 
  // Retrieve the fractional bin distances
  xFrac_ = xBinInfo.second;
  yFrac_ = yBinInfo.second;
  zFrac_ = zBinInfo.second;
 
  // Set the complimentary fractional bin distances
  xFrac1_ = 1.0 - xFrac_;
  yFrac1_ = 1.0 - yFrac_;
  zFrac1_ = 1.0 - zFrac_;
 
  // Finally get the magnetic field components using trilinear interpolation
  // and scale with the appropriate multiplication factor (default = 1.0)
  B[0] = this->BInterCalc(ShipBFieldMap::xAxis) * scale_ * BxSign;
  B[1] = this->BInterCalc(ShipBFieldMap::yAxis) * scale_;
  B[2] = this->BInterCalc(ShipBFieldMap::zAxis) * scale_ * BzSign;
}

getBinInfo()

ShipBFieldMap::binPair ShipBFieldMap::getBinInfo ( Float_t  x, ShipBFieldMap::CoordAxis  theAxis  )

private

Get the bin number and fractional distance from the leftmost bin edge.

Parameters

[in]	x	The coordinate component of the point (cm)
[in]	theAxis	The coordinate axis (CoordAxis enumeration for x, y or z)

Returns

the bin number and fractional distance from the leftmost bin edge as a pair

Definition at line 422 of file ShipBFieldMap.cxx.

                                               {
  Float_t du(0.0), uMin(0.0), Nu(0);
 
  if (theAxis == ShipBFieldMap::xAxis) {
    du = dx_;
    uMin = xMin_;
    Nu = Nx_;
  } else if (theAxis == ShipBFieldMap::yAxis) {
    du = dy_;
    uMin = yMin_;
    Nu = Ny_;
  } else if (theAxis == ShipBFieldMap::zAxis) {
    du = dz_;
    uMin = zMin_;
    Nu = Nz_;
  }
 
  Int_t iBin(-1);
  Float_t fracL(0.0);
 
  if (du > 1e-10) {
    // Get the number of fractional bin widths the point is from the first
    // volume bin
    Float_t dist = (u - uMin) / du;
    // Get the integer equivalent of this distance, which is the bin number
    iBin = static_cast<Int_t>(dist);
    // Get the actual fractional distance of the point from the leftmost bin
    // edge
    fracL = (dist - iBin * 1.0);
  }
 
  // Check that the bin number is valid
  if (iBin < 0 || iBin >= Nu) {
    iBin = -1;
    fracL = 0.0;
  }
 
  // Return the bin number and fractional distance of the point from the
  // leftmost bin edge
  binPair binInfo(iBin, fracL);
 
  return binInfo;
}

GetdX()

Float_t ShipBFieldMap::GetdX ( ) const

inline

Get the bin width along x for the map.

Returns

the bin width along x (cm)

Definition at line 187 of file ShipBFieldMap.h.

{ return dx_; }

GetdY()

Float_t ShipBFieldMap::GetdY ( ) const

inline

Get the bin width along y for the map.

Returns

the bin width along y (cm)

Definition at line 211 of file ShipBFieldMap.h.

{ return dy_; }

GetdZ()

Float_t ShipBFieldMap::GetdZ ( ) const

inline

Get the bin width along z for the map.

Returns

the bin width along z (cm)

Definition at line 235 of file ShipBFieldMap.h.

{ return dz_; }

getFieldMap()

floatArray * ShipBFieldMap::getFieldMap ( ) const

inline

Retrieve the field map.

Returns

the field map

Definition at line 89 of file ShipBFieldMap.h.

{ return fieldMap_; }

getMapBin()

Int_t ShipBFieldMap::getMapBin ( Int_t  iX, Int_t  iY, Int_t  iZ  )

private

Find the vector entry of the field map data given the bins iX, iY and iZ.

Parameters

[in]	iX	The bin along the x axis
[in]	iY	The bin along the y axis
[in]	iZ	The bin along the z axis

Returns

the index entry for the field map data vector

Definition at line 467 of file ShipBFieldMap.cxx.

                                                           {
  // Get the index of the map entry corresponding to the x,y,z bins.
  // Remember that the map is ordered in ascending z, y, then x
 
  Int_t index = (iX * Ny_ + iY) * Nz_ + iZ;
  if (index < 0) {
    index = 0;
  } else if (index >= N_) {
    index = N_ - 1;
  }
 
  return index;
}

GetMapFileName()

std::string ShipBFieldMap::GetMapFileName ( ) const

inline

Get the name of the map file.

Returns

the name of the map file as an STL string

Definition at line 145 of file ShipBFieldMap.h.

{ return mapFileName_; }

GetNBins()

Int_t ShipBFieldMap::GetNBins ( ) const

inline

Get the total number of bins.

Returns

the total number of bins

Definition at line 169 of file ShipBFieldMap.h.

{ return N_; }

GetNx()

Int_t ShipBFieldMap::GetNx ( ) const

inline

Get the number of bins along x.

Returns

the number of bins along x

Definition at line 151 of file ShipBFieldMap.h.

{ return Nx_; }

GetNy()

Int_t ShipBFieldMap::GetNy ( ) const

inline

Get the number of bins along y.

Returns

the number of bins along y

Definition at line 157 of file ShipBFieldMap.h.

{ return Ny_; }

GetNz()

Int_t ShipBFieldMap::GetNz ( ) const

inline

Get the number of bins along z.

Returns

the number of bins along z

Definition at line 163 of file ShipBFieldMap.h.

{ return Nz_; }

GetPhi()

Float_t ShipBFieldMap::GetPhi ( ) const

inline

Get the first Euler rotation angle about the z axis for global positioning.

Returns

the map's first Euler rotation angle about the z axis (degrees)

Definition at line 265 of file ShipBFieldMap.h.

{ return phi_; }

GetPsi()

Float_t ShipBFieldMap::GetPsi ( ) const

inline

Get the third Euler rotation angle about the new z axis for global positioning

Returns

the map's third Euler rotation angle about the new z axis (degrees)

Definition at line 280 of file ShipBFieldMap.h.

{ return psi_; }

GetScale()

Float_t ShipBFieldMap::GetScale ( ) const

inline

Get the field magnitude scaling factor.

Returns

the scaling factor for the field magnitude

Definition at line 286 of file ShipBFieldMap.h.

{ return scale_; }

GetTheta()

Float_t ShipBFieldMap::GetTheta ( ) const

inline

Get the second Euler rotation angle about the new x axis for global positioning

Returns

the map's second Euler rotation angle about the new x axis (degrees)

Definition at line 273 of file ShipBFieldMap.h.

{ return theta_; }

GetXMax()

Float_t ShipBFieldMap::GetXMax ( ) const

inline

Get the maximum value of x for the map.

Returns

the maximum x coordinate (cm)

Definition at line 181 of file ShipBFieldMap.h.

{ return xMax_; }

GetXMin()

Float_t ShipBFieldMap::GetXMin ( ) const

inline

Get the minimum value of x for the map.

Returns

the minimum x coordinate (cm)

Definition at line 175 of file ShipBFieldMap.h.

{ return xMin_; }

GetXOffset()

Float_t ShipBFieldMap::GetXOffset ( ) const

inline

Get the x offset coordinate of the map for global positioning.

Returns

the map's x offset coordinate for global positioning (cm)

Definition at line 247 of file ShipBFieldMap.h.

{ return xOffset_; }

GetXRange()

Float_t ShipBFieldMap::GetXRange ( ) const

inline

Get the x coordinate range for the map.

Returns

the x coordinate range (cm)

Definition at line 193 of file ShipBFieldMap.h.

{ return xRange_; }

GetYMax()

Float_t ShipBFieldMap::GetYMax ( ) const

inline

Get the maximum value of y for the map.

Returns

the maximum y coordinate (cm)

Definition at line 205 of file ShipBFieldMap.h.

{ return yMax_; }

GetYMin()

Float_t ShipBFieldMap::GetYMin ( ) const

inline

Get the minimum value of y for the map.

Returns

the minimum y coordinate (cm)

Definition at line 199 of file ShipBFieldMap.h.

{ return yMin_; }

GetYOffset()

Float_t ShipBFieldMap::GetYOffset ( ) const

inline

Get the y offset coordinate of the map for global positioning.

Returns

the map's y offset coordinate for global positioning (cm)

Definition at line 253 of file ShipBFieldMap.h.

{ return yOffset_; }

GetYRange()

Float_t ShipBFieldMap::GetYRange ( ) const

inline

Get the y coordinate range for the map.

Returns

the y coordinate range (cm)

Definition at line 217 of file ShipBFieldMap.h.

{ return yRange_; }

GetZMax()

Float_t ShipBFieldMap::GetZMax ( ) const

inline

Get the maximum value of z for the map.

Returns

the maximum z coordinate (cm)

Definition at line 229 of file ShipBFieldMap.h.

{ return zMax_; }

GetZMin()

Float_t ShipBFieldMap::GetZMin ( ) const

inline

Get the minimum value of z for the map.

Returns

the minimum z coordinate (cm)

Definition at line 223 of file ShipBFieldMap.h.

{ return zMin_; }

GetZOffset()

Float_t ShipBFieldMap::GetZOffset ( ) const

inline

Get the z offset coordinate of the map for global positioning.

Returns

the map's z offset coordinate for global positioning (cm)

Definition at line 259 of file ShipBFieldMap.h.

{ return zOffset_; }

GetZRange()

Float_t ShipBFieldMap::GetZRange ( ) const

inline

Get the z coordinate range for the map.

Returns

the z coordinate range (cm)

Definition at line 241 of file ShipBFieldMap.h.

{ return zRange_; }

HasSymmetry()

Bool_t ShipBFieldMap::HasSymmetry ( ) const

inline

Get the boolean flag to specify if we have quadrant symmetry.

Returns

the boolean specifying if we have quadrant symmetry

Definition at line 292 of file ShipBFieldMap.h.

{ return isSymmetric_; }

initialise()

void ShipBFieldMap::initialise ( )

private

Initialisation.

Definition at line 216 of file ShipBFieldMap.cxx.

                               {
  if (initialised_ == kFALSE) {
    if (isCopy_ == kFALSE) {
      this->readMapFile();
    }
 
    // Set the global coordinate translation and rotation info
    if (fabs(phi_) > 1e-6 || fabs(theta_) > 1e-6 || fabs(psi_) > 1e-6) {
      // We have non-zero rotation angles. Create a combined translation and
      // rotation
      TGeoTranslation tr("offsets", xOffset_, yOffset_, zOffset_);
      TGeoRotation rot("angles", phi_, theta_, psi_);
      theTrans_ = new TGeoCombiTrans(tr, rot);
 
    } else {
      // We only need a translation
      theTrans_ = new TGeoTranslation("offsets", xOffset_, yOffset_, zOffset_);
    }
 
    initialised_ = kTRUE;
  }
}

insideRange()

Bool_t ShipBFieldMap::insideRange ( Float_t  x, Float_t  y, Float_t  z  )

private

Check to see if a point is within the map validity range.

Parameters

[in]	x	The x coordinate of the point (cm)
[in]	y	The y coordinate of the point (cm)
[in]	z	The z coordinate of the point (cm)

Returns

true/false if the point is inside the field map range

Definition at line 375 of file ShipBFieldMap.cxx.

                                                                 {
  Bool_t inside(kFALSE);
 
  if (x >= xMin_ && x <= xMax_ && y >= yMin_ && y <= yMax_ && z >= zMin_ &&
      z <= zMax_) {
    inside = kTRUE;
  }
 
  return inside;
}

IsACopy()

Bool_t ShipBFieldMap::IsACopy ( ) const

inline

Get the boolean flag to specify if we are a "copy".

Returns

the boolean copy flag status

Definition at line 298 of file ShipBFieldMap.h.

{ return isCopy_; }

operator=()

ShipBFieldMap & ShipBFieldMap::operator= ( const ShipBFieldMap &  rhs )

privatedelete

readMapFile()

void ShipBFieldMap::readMapFile ( )

private

Read the field map data and store the information internally.

Definition at line 239 of file ShipBFieldMap.cxx.

                                {
  LOG(info) << "ShipBFieldMap::readMapFile() creating field " << this->GetName()
            << " using file " << mapFileName_;
 
  // Check to see if we have a ROOT file
  if (mapFileName_.find(".root") != std::string::npos) {
    this->readRootFile();
 
  } else {
    this->readTextFile();
  }
}

readRootFile()

void ShipBFieldMap::readRootFile ( )

private

Process the ROOT file containing the field map data.

Definition at line 252 of file ShipBFieldMap.cxx.

                                 {
  TFile* theFile = TFile::Open(mapFileName_.c_str());
 
  if (!theFile) {
    LOG(fatal) << "ShipBFieldMap: could not find the file " << mapFileName_;
  }
 
  // Coordinate ranges
  TTree* rTree = dynamic_cast<TTree*>(theFile->Get("Range"));
  if (!rTree) {
    LOG(fatal) << "ShipBFieldMap: could not find Range tree in "
               << mapFileName_;
  }
 
  rTree->SetBranchAddress("xMin", &xMin_);
  rTree->SetBranchAddress("xMax", &xMax_);
  rTree->SetBranchAddress("dx", &dx_);
  rTree->SetBranchAddress("yMin", &yMin_);
  rTree->SetBranchAddress("yMax", &yMax_);
  rTree->SetBranchAddress("dy", &dy_);
  rTree->SetBranchAddress("zMin", &zMin_);
  rTree->SetBranchAddress("zMax", &zMax_);
  rTree->SetBranchAddress("dz", &dz_);
 
  // Fill the ranges
  rTree->GetEntry(0);
 
  this->setLimits();
 
  // Make sure we don't have a copy
  if (isCopy_ == kFALSE) {
    // The data is expected to contain Bx,By,Bz data values
    // in ascending z,y,x coordinate order
 
    TTree* dTree = dynamic_cast<TTree*>(theFile->Get("Data"));
    if (!dTree) {
      LOG(fatal) << "ShipBFieldMap: could not find Data tree in "
                 << mapFileName_;
    }
 
    Float_t Bx, By, Bz;
    // Only enable the field components
    dTree->SetBranchStatus("*", 0);
    dTree->SetBranchStatus("Bx", 1);
    dTree->SetBranchStatus("By", 1);
    dTree->SetBranchStatus("Bz", 1);
 
    dTree->SetBranchAddress("Bx", &Bx);
    dTree->SetBranchAddress("By", &By);
    dTree->SetBranchAddress("Bz", &Bz);
 
    Int_t nEntries = dTree->GetEntries();
    if (nEntries != N_) {
      LOG(fatal) << "Expected " << N_ << " field map entries but found "
                 << nEntries;
      nEntries = 0;
    }
 
    fieldMap_->reserve(nEntries);
 
    for (Int_t i = 0; i < nEntries; i++) {
      dTree->GetEntry(i);
 
      // B field values are in Tesla. This means these values are multiplied
      // by a factor of ten since both FairRoot and the VMC interface use kGauss
      Bx *= Tesla_;
      By *= Tesla_;
      Bz *= Tesla_;
 
      // Store the B field 3-vector
      fieldMap_->push_back({Bx, By, Bz});
    }
  }
 
  theFile->Close();
}

readTextFile()

void ShipBFieldMap::readTextFile ( )

private

Process the text file containing the field map data.

Definition at line 329 of file ShipBFieldMap.cxx.

                                 {
  std::ifstream getData(mapFileName_.c_str());
 
  if (!getData.is_open()) {
    LOG(fatal) << "Error: Cannot open magnetic field map file: "
               << mapFileName_;
  }
 
  std::string tmpString("");
 
  getData >> tmpString >> xMin_ >> xMax_ >> dx_ >> yMin_ >> yMax_ >> dy_ >>
      zMin_ >> zMax_ >> dz_;
 
  this->setLimits();
 
  // Check to see if this object is a "copy"
  if (isCopy_ == kFALSE) {
    // Read the field map and store the magnetic field components
 
    // Second line can be ignored since they are
    // just labels for the data columns for readability
    getData >> tmpString >> tmpString >> tmpString;
 
    // The remaining lines contain Bx,By,Bz data values
    // in ascending z,y,x co-ord order
    fieldMap_->reserve(N_);
 
    Float_t Bx(0.0), By(0.0), Bz(0.0);
 
    for (Int_t i = 0; i < N_; i++) {
      getData >> Bx >> By >> Bz;
 
      // B field values are in Tesla. This means these values are multiplied
      // by a factor of ten since both FairRoot and the VMC interface use kGauss
      Bx *= Tesla_;
      By *= Tesla_;
      Bz *= Tesla_;
 
      // Store the B field 3-vector
      fieldMap_->push_back({Bx, By, Bz});
    }
  }
 
  getData.close();
}

setLimits()

void ShipBFieldMap::setLimits ( )

private

Definition at line 386 of file ShipBFieldMap.cxx.

                              {
  // Since the default SHIP distance unit is cm, we do not need to convert
  // these map limits, i.e. cm = 1 already
 
  xRange_ = xMax_ - xMin_;
  yRange_ = yMax_ - yMin_;
  zRange_ = zMax_ - zMin_;
 
  // Find the number of bins using the limits and bin sizes. The number of bins
  // includes both the minimum and maximum values. To ensure correct rounding
  // up to the nearest integer we need to add 1.5 not 1.0.
  if (dx_ > 0.0) {
    Nx_ = static_cast<Int_t>(((xMax_ - xMin_) / dx_) + 1.5);
  }
  if (dy_ > 0.0) {
    Ny_ = static_cast<Int_t>(((yMax_ - yMin_) / dy_) + 1.5);
  }
  if (dz_ > 0.0) {
    Nz_ = static_cast<Int_t>(((zMax_ - zMin_) / dz_) + 1.5);
  }
 
  N_ = Nx_ * Ny_ * Nz_;
 
  LOG(info) << "x limits: " << xMin_ << ", " << xMax_ << ", dx = " << dx_;
  LOG(info) << "y limits: " << yMin_ << ", " << yMax_ << ", dy = " << dy_;
  LOG(info) << "z limits: " << zMin_ << ", " << zMax_ << ", dz = " << dz_;
 
  LOG(info) << "Offsets: x = " << xOffset_ << ", y = " << yOffset_
            << ", z = " << zOffset_;
  LOG(info) << "Angles : phi = " << phi_ << ", theta = " << theta_
            << ", psi = " << psi_;
 
  LOG(info) << "Total number of bins = " << N_ << "; Nx = " << Nx_
            << ", Ny = " << Ny_ << ", Nz = " << Nz_;
}

SetPhi()

void ShipBFieldMap::SetPhi ( Float_t  phi )

inline

Set the first Euler rotation angle phi about the z axis.

Parameters

[in]

phi

The first Euler rotation angle about the z axis (degrees)

Definition at line 113 of file ShipBFieldMap.h.

{ phi_ = phi; }

SetPsi()

void ShipBFieldMap::SetPsi ( Float_t  psi )

inline

Set the third Euler rotation angle psi about the new z axis.

Parameters

[in]

psi

The third Euler rotation angle about the new z axis (degrees)

Definition at line 127 of file ShipBFieldMap.h.

{ psi_ = psi; }

SetScale()

void ShipBFieldMap::SetScale ( Float_t  scale )

inline

Set the field magnitude scaling factor.

Parameters

[in]

scale

The scaling factor for the field magnitude

Definition at line 133 of file ShipBFieldMap.h.

{ scale_ = scale; }

SetTheta()

void ShipBFieldMap::SetTheta ( Float_t  theta )

inline

Set the second Euler rotation angle theta about the new x axis.

Parameters

[in]

theta

The second Euler rotation angle about the new x axis (degrees)

Definition at line 120 of file ShipBFieldMap.h.

{ theta_ = theta; }

SetXOffset()

void ShipBFieldMap::SetXOffset ( Float_t  xValue )

inline

Set the x global coordinate shift.

Parameters

[in]

xValue

The value of the x global coordinate shift (cm)

Definition at line 95 of file ShipBFieldMap.h.

{ xOffset_ = xValue; }

SetYOffset()

void ShipBFieldMap::SetYOffset ( Float_t  yValue )

inline

Set the y global coordinate shift.

Parameters

[in]

yValue

The value of the y global coordinate shift (cm)

Definition at line 101 of file ShipBFieldMap.h.

{ yOffset_ = yValue; }

SetZOffset()

void ShipBFieldMap::SetZOffset ( Float_t  zValue )

inline

Set the z global coordinate shift.

Parameters

[in]

zValue

The value of the z global coordinate shift (cm)

Definition at line 107 of file ShipBFieldMap.h.

{ zOffset_ = zValue; }

UseSymmetry()

void ShipBFieldMap::UseSymmetry ( Bool_t  flag )

inline

Set the boolean to specify if we have quadrant symmetry.

Parameters

[in]

isSymmetric

Boolean to specify if we have quadrant symmetry

Definition at line 139 of file ShipBFieldMap.h.

{ isSymmetric_ = flag; }

Member Data Documentation

binA_

Int_t ShipBFieldMap::binA_

private

Bin A for the trilinear interpolation.

Definition at line 459 of file ShipBFieldMap.h.

binB_

Int_t ShipBFieldMap::binB_

private

Bin B for the trilinear interpolation.

Definition at line 462 of file ShipBFieldMap.h.

binC_

Int_t ShipBFieldMap::binC_

private

Bin C for the trilinear interpolation.

Definition at line 465 of file ShipBFieldMap.h.

binD_

Int_t ShipBFieldMap::binD_

private

Bin D for the trilinear interpolation.

Definition at line 468 of file ShipBFieldMap.h.

binE_

Int_t ShipBFieldMap::binE_

private

Bin E for the trilinear interpolation.

Definition at line 471 of file ShipBFieldMap.h.

binF_

Int_t ShipBFieldMap::binF_

private

Bin F for the trilinear interpolation.

Definition at line 474 of file ShipBFieldMap.h.

binG_

Int_t ShipBFieldMap::binG_

private

Bin G for the trilinear interpolation.

Definition at line 477 of file ShipBFieldMap.h.

binH_

Int_t ShipBFieldMap::binH_

private

Bin H for the trilinear interpolation.

Definition at line 480 of file ShipBFieldMap.h.

dx_

Float_t ShipBFieldMap::dx_

private

The bin width along x.

Definition at line 399 of file ShipBFieldMap.h.

dy_

Float_t ShipBFieldMap::dy_

private

The bin width along y.

Definition at line 411 of file ShipBFieldMap.h.

dz_

Float_t ShipBFieldMap::dz_

private

The bin width along z.

Definition at line 423 of file ShipBFieldMap.h.

fieldMap_

floatArray* ShipBFieldMap::fieldMap_

private

Store the field map information as a vector of 3 floats. Map data ordering is given by first incrementing z, then y, then x

Definition at line 368 of file ShipBFieldMap.h.

initialised_

Bool_t ShipBFieldMap::initialised_

private

Initialisation boolean.

Definition at line 374 of file ShipBFieldMap.h.

isCopy_

Bool_t ShipBFieldMap::isCopy_

private

Flag to specify if we are a copy of the field map (just a change of global offsets)

Definition at line 378 of file ShipBFieldMap.h.

isSymmetric_

Bool_t ShipBFieldMap::isSymmetric_

private

The boolean specifying if we have quadrant symmetry.

Definition at line 450 of file ShipBFieldMap.h.

mapFileName_

std::string ShipBFieldMap::mapFileName_

private

The name of the map file.

Definition at line 371 of file ShipBFieldMap.h.

N_

Int_t ShipBFieldMap::N_

private

The total number of bins.

Definition at line 390 of file ShipBFieldMap.h.

Nx_

Int_t ShipBFieldMap::Nx_

private

The number of bins along x.

Definition at line 381 of file ShipBFieldMap.h.

Ny_

Int_t ShipBFieldMap::Ny_

private

The number of bins along y.

Definition at line 384 of file ShipBFieldMap.h.

Nz_

Int_t ShipBFieldMap::Nz_

private

The number of bins along z.

Definition at line 387 of file ShipBFieldMap.h.

phi_

Float_t ShipBFieldMap::phi_

private

The first Euler rotation angle about the z axis.

Definition at line 438 of file ShipBFieldMap.h.

psi_

Float_t ShipBFieldMap::psi_

private

The third Euler rotation angle about the new z axis.

Definition at line 444 of file ShipBFieldMap.h.

scale_

Float_t ShipBFieldMap::scale_

private

The B field magnitude scaling factor.

Definition at line 447 of file ShipBFieldMap.h.

Tesla_

Float_t ShipBFieldMap::Tesla_

private

Double converting Tesla to kiloGauss (for VMC/FairRoot B field units)

Definition at line 456 of file ShipBFieldMap.h.

theta_

Float_t ShipBFieldMap::theta_

private

The second Euler rotation angle about the new x axis.

Definition at line 441 of file ShipBFieldMap.h.

theTrans_

TGeoMatrix* ShipBFieldMap::theTrans_

private

The combined translation and rotation transformation.

Definition at line 453 of file ShipBFieldMap.h.

xFrac1_

Float_t ShipBFieldMap::xFrac1_

private

Complimentary fractional bin distance along x.

Definition at line 492 of file ShipBFieldMap.h.

xFrac_

Float_t ShipBFieldMap::xFrac_

private

Fractional bin distance along x.

Definition at line 483 of file ShipBFieldMap.h.

xMax_

Float_t ShipBFieldMap::xMax_

private

The maximum value of x for the map.

Definition at line 396 of file ShipBFieldMap.h.

xMin_

Float_t ShipBFieldMap::xMin_

private

The minimum value of x for the map.

Definition at line 393 of file ShipBFieldMap.h.

xOffset_

Float_t ShipBFieldMap::xOffset_

private

The x value of the positional offset for the map.

Definition at line 429 of file ShipBFieldMap.h.

xRange_

Float_t ShipBFieldMap::xRange_

private

The coordinate range along x.

Definition at line 402 of file ShipBFieldMap.h.

yFrac1_

Float_t ShipBFieldMap::yFrac1_

private

Complimentary fractional bin distance along y.

Definition at line 495 of file ShipBFieldMap.h.

yFrac_

Float_t ShipBFieldMap::yFrac_

private

Fractional bin distance along y.

Definition at line 486 of file ShipBFieldMap.h.

yMax_

Float_t ShipBFieldMap::yMax_

private

The maximum value of y for the map.

Definition at line 408 of file ShipBFieldMap.h.

yMin_

Float_t ShipBFieldMap::yMin_

private

The minimum value of y for the map.

Definition at line 405 of file ShipBFieldMap.h.

yOffset_

Float_t ShipBFieldMap::yOffset_

private

The y value of the positional offset for the map.

Definition at line 432 of file ShipBFieldMap.h.

yRange_

Float_t ShipBFieldMap::yRange_

private

The coordinate range along y.

Definition at line 414 of file ShipBFieldMap.h.

zFrac1_

Float_t ShipBFieldMap::zFrac1_

private

Complimentary fractional bin distance along z.

Definition at line 498 of file ShipBFieldMap.h.

zFrac_

Float_t ShipBFieldMap::zFrac_

private

Fractional bin distance along z.

Definition at line 489 of file ShipBFieldMap.h.

zMax_

Float_t ShipBFieldMap::zMax_

private

The maximum value of z for the map.

Definition at line 420 of file ShipBFieldMap.h.

zMin_

Float_t ShipBFieldMap::zMin_

private

The minimum value of z for the map.

Definition at line 417 of file ShipBFieldMap.h.

zOffset_

Float_t ShipBFieldMap::zOffset_

private

The z value of the positional offset for the map.

Definition at line 435 of file ShipBFieldMap.h.

zRange_

Float_t ShipBFieldMap::zRange_

private

The coordinate range along z.

Definition at line 426 of file ShipBFieldMap.h.

---

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

• field/ShipBFieldMap.h
• field/ShipBFieldMap.cxx