BFieldCacheZR Class Reference

#include <BFieldCacheZR.h>

Collaboration diagram for BFieldCacheZR:

Public Member Functions
void	invalidate ()
void	setRange (double zmin, double zmax, double rmin, double rmax)
void	setField (int i, const BFieldVectorZR &field, double scaleFactor=1.0)
bool	inside (double z, double r) const
void	getB (const double *ATH_RESTRICT xyz, double r, double *ATH_RESTRICT B, double *ATH_RESTRICT deriv=nullptr) const

Private Attributes
double	m_zmin {0}
double	m_zmax {-1}
double	m_rmin {0}
double	m_rmax {-1}
double	m_invz {-1}
double	m_invr {-1}
double	m_field [2][4]

Detailed Description

Definition at line 21 of file BFieldCacheZR.h.

Member Function Documentation

getB()

void BFieldCacheZR::getB	(	const double *ATH_RESTRICT	xyz,
		double	r,
		double *ATH_RESTRICT	B,
		double *ATH_RESTRICT	deriv = nullptr
	)		const

Definition at line 9 of file BFieldCacheZR.cxx.

{
  const double x = xyz[0];
  const double y = xyz[1];
  const double z = xyz[2];
  // fractional position inside this bin
  const double fz = (z - m_zmin) * m_invz;
  const double gz = 1.0 - fz;
  const double fr = (r - m_rmin) * m_invr;
  const double gr = 1.0 - fr;
  // interpolate field values in z, r
  double Bzr[2];
  for (int i = 0; i < 2; ++i) { // z, r components
    const double* field = m_field[i];
    Bzr[i] = gz * (gr * field[0] + fr * field[1]) +
             fz * (gr * field[2] + fr * field[3]);
  }
  // convert (Bz,Br) to (Bx,By,Bz)
  double invr;
  if (r > 0.0) {
    invr = 1.0 / r;
  } else {
    invr = 0.0;
  }
  const double c(x * invr);
  const double s(y * invr);
  B[0] = Bzr[1] * c;
  B[1] = Bzr[1] * s;
  B[2] = Bzr[0];
 
  // compute field derivatives if requested
  if (deriv) {
    std::array<double, 2> dBdz{};
    std::array<double, 2> dBdr{};
    for (int j = 0; j < 2; ++j) { // Bz, Br components
      const double* field = m_field[j];
      dBdz[j] =
        m_invz * (gr * (field[2] - field[0]) + fr * (field[3] - field[1]));
      dBdr[j] =
        m_invr * (gz * (field[1] - field[0]) + fz * (field[3] - field[2]));
    }
    // convert to cartesian coordinates
    const double cc = c * c;
    const double cs = c * s;
    const double ss = s * s;
    const double sinvr = s * invr;
    const double cinvr = c * invr;
    deriv[0] = cc * dBdr[1] + sinvr * B[1];
    deriv[1] = cs * dBdr[1] - cinvr * B[1];
    deriv[2] = c * dBdz[1];
    deriv[3] = cs * dBdr[1] - sinvr * B[0];
    deriv[4] = ss * dBdr[1] + cinvr * B[0];
    deriv[5] = s * dBdz[1];
    deriv[6] = c * dBdr[0];
    deriv[7] = s * dBdr[0];
    deriv[8] = dBdz[0];
  }
}

inside()

bool BFieldCacheZR::inside	(	double	z,
		double	r
	)		const

invalidate()

void BFieldCacheZR::invalidate

(

)

setField()

void BFieldCacheZR::setField	(	int	i,
		const BFieldVectorZR &	field,
		double	scaleFactor = 1.0
	)

setRange()

void BFieldCacheZR::setRange	(	double	zmin,
		double	zmax,
		double	rmin,
		double	rmax
	)

Member Data Documentation

m_field

double BFieldCacheZR::m_field[2][4]

private

Definition at line 45 of file BFieldCacheZR.h.

m_invr

double BFieldCacheZR::m_invr {-1}

private

Definition at line 44 of file BFieldCacheZR.h.

m_invz

double BFieldCacheZR::m_invz {-1}

private

Definition at line 44 of file BFieldCacheZR.h.

m_rmax

double BFieldCacheZR::m_rmax {-1}

private

Definition at line 43 of file BFieldCacheZR.h.

m_rmin

double BFieldCacheZR::m_rmin {0}

private

Definition at line 43 of file BFieldCacheZR.h.

m_zmax

double BFieldCacheZR::m_zmax {-1}

private

Definition at line 42 of file BFieldCacheZR.h.

m_zmin

double BFieldCacheZR::m_zmin {0}

private

Definition at line 42 of file BFieldCacheZR.h.

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

• BFieldCacheZR.h
• BFieldCacheZR.cxx