MagField::AtlasFieldCache Class Reference

Local cache for magnetic field (based on MagFieldServices/AtlasFieldSvcTLS.h) More...

#include <AtlasFieldCache.h>

Collaboration diagram for MagField::AtlasFieldCache:

Public Member Functions
	AtlasFieldCache ()=default
	AtlasFieldCache (double solFieldScale, double torFieldScale, const AtlasFieldMap *fieldMap)
	constructor to setup with field scale and magnetic field map for first access to field
AtlasFieldCache &	operator= (AtlasFieldCache &&other)=default
	Move-able and copy-able.
	AtlasFieldCache (AtlasFieldCache &&other)=default
	AtlasFieldCache (const AtlasFieldCache &other)=default
AtlasFieldCache &	operator= (const AtlasFieldCache &other)=default
	~AtlasFieldCache ()=default
void	getField (const double *ATH_RESTRICT xyz, double *ATH_RESTRICT bxyz, double *ATH_RESTRICT deriv=nullptr)
	get B field value at given position xyz[3] is in mm, bxyz[3] is in kT if deriv[9] is given, field derivatives are returned in kT/mm
void	getFieldZR (const double *ATH_RESTRICT xyz, double *ATH_RESTRICT bxyz, double *ATH_RESTRICT deriv=nullptr)
	get B field valaue on the z-r plane at given position works only inside the solenoid.
bool	solenoidOn () const
	status of the magnets
bool	toroidOn () const

Private Member Functions
bool	fillFieldCache (double z, double r, double phi)
	fill given magnetic field zone *‍/
bool	fillFieldCacheZR (double z, double r)
	fill Z-R cache for solenoid *‍/

Private Attributes
double	m_solScale { 1 }
	magnetic field scales from currents
double	m_torScale { 1 }
double	m_scaleToUse { 1 }
int	m_solZoneId { -1 }
const AtlasFieldMap *	m_fieldMap { nullptr }
	handle to the magnetic field map - not owned
const BFieldZone *	m_zone3d { nullptr }
	A zone of the full 3d field.
BFieldCache	m_cache3d
	Full 3d field cell/cache This will be a cell inside a 3d field zone.
const std::vector< BFieldCond > *	m_cond { nullptr }
	Pointer to the conductors in the current field zone (to compute Biot-Savart component) Owned by AtlasFieldMap.
const BFieldMeshZR *	m_meshZR { nullptr }
	fast 2d map made of one zone assuming phi/roatational symmetry Owned by AtlasFieldMap.
BFieldCacheZR	m_cacheZR {}
	Fast 2d field cell/cache.

Detailed Description

Local cache for magnetic field (based on MagFieldServices/AtlasFieldSvcTLS.h)

We keep track of the

• magnetic field map
• solenoid/toroid scales from the currents
• The current zone
• The current/cached cell in the zone.

Author

R.D.Schaffer -at- cern.ch

Definition at line 42 of file AtlasFieldCache.h.

Constructor & Destructor Documentation

AtlasFieldCache() [1/4]

MagField::AtlasFieldCache::AtlasFieldCache ( )

default

AtlasFieldCache() [2/4]

MagField::AtlasFieldCache::AtlasFieldCache	(	double	solFieldScale,
		double	torFieldScale,
		const AtlasFieldMap *	fieldMap )

constructor to setup with field scale and magnetic field map for first access to field

AtlasFieldCache() [3/4]

MagField::AtlasFieldCache::AtlasFieldCache ( AtlasFieldCache && other )

default

AtlasFieldCache() [4/4]

MagField::AtlasFieldCache::AtlasFieldCache ( const AtlasFieldCache & other )

default

~AtlasFieldCache()

MagField::AtlasFieldCache::~AtlasFieldCache ( )

default

Member Function Documentation

fillFieldCache()

bool MagField::AtlasFieldCache::fillFieldCache ( double z, double r, double phi )

private

fill given magnetic field zone *‍/

fillFieldCacheZR()

bool MagField::AtlasFieldCache::fillFieldCacheZR ( double z, double r )

private

fill Z-R cache for solenoid *‍/

getField()

void MagField::AtlasFieldCache::getField	(	const double *ATH_RESTRICT	xyz,
		double *ATH_RESTRICT	bxyz,
		double *ATH_RESTRICT	deriv = nullptr )

get B field value at given position xyz[3] is in mm, bxyz[3] is in kT if deriv[9] is given, field derivatives are returned in kT/mm

Definition at line 42 of file AtlasFieldCache.cxx.

{
  // Allow for the case of no map for testing
  if (m_fieldMap == nullptr) {
    defaultField(bxyz, deriv);
    return;
  }
 
  const double x = xyz[0];
  const double y = xyz[1];
  const double z = xyz[2];
  const double r = std::sqrt(x * x + y * y);
  const double phi = std::atan2(y, x);
 
  // Check that the cached z,r, phi cell is valid
  // and if we are still inside it
  if (!m_cache3d.inside(z, r, phi)) {
    // if not we need to find and cache a new cell
    if (!fillFieldCache(z, r, phi)) {
      // caching failed
      // outside the valid map volume
      defaultField(bxyz, deriv);
      return;
    }
  }
 
  // do interpolation (cache3d has correct scale factor)
  m_cache3d.getB(xyz, r, phi, bxyz, deriv);
 
  if (!m_cond) {
    return;
  }
  // add biot savart component - must add in scale factor to avoid changing
  // conductor SF since the conductor is part of the static magnetic field model
  const size_t condSize = m_cond->size();
  for (size_t i = 0; i < condSize; i++) {
    //Heavy Eigen use from here
    (*m_cond)[i].addBiotSavart(m_scaleToUse, xyz, bxyz, deriv);
  }
}

getFieldZR()

void MagField::AtlasFieldCache::getFieldZR	(	const double *ATH_RESTRICT	xyz,
		double *ATH_RESTRICT	bxyz,
		double *ATH_RESTRICT	deriv = nullptr )

get B field valaue on the z-r plane at given position works only inside the solenoid.

Otherwise call getField above. xyz[3] is in mm, bxyz[3] is in kT if deriv[9] is given, field derivatives are returned in kT/mm

Definition at line 86 of file AtlasFieldCache.cxx.

{
 
  // Allow for the case of no map for testing
  if (m_fieldMap == nullptr) {
    defaultField(bxyz, deriv);
    return;
  }
 
  const double x = xyz[0];
  const double y = xyz[1];
  const double z = xyz[2];
  const double r = std::sqrt(x * x + y * y);
 
  // Check that the cached z,r, cell is valid
  // and if we are still inside it
  if (!m_cacheZR.inside(z, r)) {
    // cached cell is invalid -> refresh cached cell
    if (!fillFieldCacheZR(z, r)) {
      // No cell found -> outside the valid z-r map volume
      // fallback to calling
      // the full version of getField()
      getField(xyz, bxyz, deriv);
      return;
    }
  }
  // do interpolation
  m_cacheZR.getB(xyz, r, bxyz, deriv);
}

operator=() [1/2]

AtlasFieldCache & MagField::AtlasFieldCache::operator= ( AtlasFieldCache && other )

default

Move-able and copy-able.

operator=() [2/2]

AtlasFieldCache & MagField::AtlasFieldCache::operator= ( const AtlasFieldCache & other )

default

solenoidOn()

bool MagField::AtlasFieldCache::solenoidOn

(

)

const

status of the magnets

toroidOn()

bool MagField::AtlasFieldCache::toroidOn

(

)

const

Member Data Documentation

m_cache3d

BFieldCache MagField::AtlasFieldCache::m_cache3d

private

Full 3d field cell/cache This will be a cell inside a 3d field zone.

Definition at line 113 of file AtlasFieldCache.h.

m_cacheZR

BFieldCacheZR MagField::AtlasFieldCache::m_cacheZR {}

private

Fast 2d field cell/cache.

Definition at line 125 of file AtlasFieldCache.h.

{};

m_cond

const std::vector<BFieldCond>* MagField::AtlasFieldCache::m_cond { nullptr }

private

Pointer to the conductors in the current field zone (to compute Biot-Savart component) Owned by AtlasFieldMap.

Definition at line 117 of file AtlasFieldCache.h.

{ nullptr };

m_fieldMap

const AtlasFieldMap* MagField::AtlasFieldCache::m_fieldMap { nullptr }

private

handle to the magnetic field map - not owned

Definition at line 102 of file AtlasFieldCache.h.

{ nullptr };

m_meshZR

const BFieldMeshZR* MagField::AtlasFieldCache::m_meshZR { nullptr }

private

fast 2d map made of one zone assuming phi/roatational symmetry Owned by AtlasFieldMap.

Definition at line 122 of file AtlasFieldCache.h.

{ nullptr };

m_scaleToUse

double MagField::AtlasFieldCache::m_scaleToUse { 1 }

private

Definition at line 95 of file AtlasFieldCache.h.

{ 1 };

m_solScale

double MagField::AtlasFieldCache::m_solScale { 1 }

private

magnetic field scales from currents

Definition at line 93 of file AtlasFieldCache.h.

{ 1 };

m_solZoneId

int MagField::AtlasFieldCache::m_solZoneId { -1 }

private

Definition at line 99 of file AtlasFieldCache.h.

{ -1 };

m_torScale

double MagField::AtlasFieldCache::m_torScale { 1 }

private

Definition at line 94 of file AtlasFieldCache.h.

{ 1 };

m_zone3d

const BFieldZone* MagField::AtlasFieldCache::m_zone3d { nullptr }

private

A zone of the full 3d field.

This can be solenoid or one of the toroid etc zones Owned by AtlasFieldMap

Definition at line 108 of file AtlasFieldCache.h.

{ nullptr };

---

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

• AtlasFieldCache.h
• AtlasFieldCache.cxx