BFieldCond Class Reference

#include <BFieldCond.h>

Collaboration diagram for BFieldCond:

Public Member Functions
	BFieldCond (bool finite, const double *p1, const double *p2, double curr)
void	addBiotSavart (double scaleFactor, const double *ATH_RESTRICT xyz, double *ATH_RESTRICT B, double *ATH_RESTRICT deriv=nullptr) const
void	scaleCurrent (double factor)
bool	finite () const
double	p1 (int i) const
double	p2 (int i) const
double	curr () const

Private Attributes
bool	m_finite
const Eigen::Vector3d	m_p1
const Eigen::Vector3d	m_p2
const Eigen::Vector3d	m_u
double	m_curr
double	m_nomCurr

Detailed Description

Definition at line 21 of file BFieldCond.h.

Constructor & Destructor Documentation

BFieldCond()

BFieldCond::BFieldCond ( bool  finite, const double *  p1, const double *  p2, double  curr  )

inline

Definition at line 25 of file BFieldCond.h.

    : m_finite(finite)
    , m_p1(Eigen::Map<const Eigen::Vector3d>(p1))
    , m_p2(Eigen::Map<const Eigen::Vector3d>(p2))
    , m_u(finite ? (m_p2 - m_p1).normalized() : m_p2)
    , m_curr(curr)
    , m_nomCurr(curr)
  {}

Member Function Documentation

addBiotSavart()

ATH_FLATTEN void BFieldCond::addBiotSavart	(	double	scaleFactor,
		const double *ATH_RESTRICT	xyz,
		double *ATH_RESTRICT	B,
		double *ATH_RESTRICT	deriv = nullptr
	)		const

Definition at line 21 of file BFieldCond.cxx.

{
  static const double mu04pi = 1.0e-7;    // mu_0/4pi
  static const double minvsq = 10. * 10.; // (1 cm)^2
 
  const Eigen::Map<const Eigen::Vector3d> pos(xyz);
  Eigen::Map<Eigen::Vector3d> B(B_in);
 
  const Eigen::Vector3d r1 = pos - m_p1;
  const Eigen::Vector3d r2 = pos - m_p2;
  const Eigen::Vector3d v = m_u.cross(r1);
  const double vsq = std::max(v.squaredNorm(), minvsq);
 
  const double r1u = r1.dot(m_u);
 
  const double r2u = r2.dot(m_u);
  const double r1n = r1.norm();
 
  const double r2n = r2.norm();
 
  const double f0 = mu04pi * m_curr * scaleFactor / vsq;
  const double f1 = f0 * (m_finite ? r1u / r1n - r2u / r2n : 2.0);
  const double f2 = 2.0 * f1 / vsq;
 
  B += f1 * v;
 
  if (deriv) {
    Eigen::Map<Eigen::Matrix<double, 3, 3, Eigen::RowMajor>> D(deriv);
 
    D(0, 1) -= f1 * m_u(2);
    D(0, 2) += f1 * m_u(1);
    D(1, 0) += f1 * m_u(2);
    D(1, 2) -= f1 * m_u(0);
    D(2, 0) -= f1 * m_u(1);
    D(2, 1) += f1 * m_u(0);
 
    if (vsq > minvsq) {
      Eigen::Vector3d w = f2 * (m_u * r1u - r1);
 
      if (m_finite) {
        // Finite conductor segment
        w += f0 * ((m_u - r1 * r1u / (r1n * r1n)) / r1n -
                   (m_u - r2 * r2u / (r2n * r2n)) / r2n);
      }
 
      D += v * w.transpose();
    }
  }
}

curr()

double BFieldCond::curr ( ) const

inline

Definition at line 48 of file BFieldCond.h.

{ return m_curr; }

finite()

bool BFieldCond::finite ( ) const

inline

Definition at line 45 of file BFieldCond.h.

{ return m_finite; }

p1()

double BFieldCond::p1 ( int  i ) const

inline

Definition at line 46 of file BFieldCond.h.

{ return m_p1[i]; }

p2()

double BFieldCond::p2 ( int  i ) const

inline

Definition at line 47 of file BFieldCond.h.

{ return m_p2[i]; }

scaleCurrent()

void BFieldCond::scaleCurrent ( double  factor )

inline

Definition at line 43 of file BFieldCond.h.

{ m_curr = factor * m_nomCurr; }

Member Data Documentation

m_curr

double BFieldCond::m_curr

private

Definition at line 59 of file BFieldCond.h.

m_finite

bool BFieldCond::m_finite

private

Definition at line 51 of file BFieldCond.h.

m_nomCurr

double BFieldCond::m_nomCurr

private

Definition at line 60 of file BFieldCond.h.

m_p1

const Eigen::Vector3d BFieldCond::m_p1

private

Definition at line 58 of file BFieldCond.h.

m_p2

const Eigen::Vector3d BFieldCond::m_p2

private

Definition at line 58 of file BFieldCond.h.

m_u

const Eigen::Vector3d BFieldCond::m_u

private

Definition at line 58 of file BFieldCond.h.

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

• BFieldCond.h
• BFieldCond.cxx