dd/d1a/BFieldCond_8h_source.html

/*

  Copyright (C) 2002-2020 CERN for the benefit of the ATLAS collaboration

*/


//

// BFieldCond.h

//

// Current conductors used in BFieldZone.

// It may be finite : p1 to p2.

// It may be infinite : passing p1 and direction parallel to p2.

//

// Masahiro Morii, Harvard University

//

#ifndef BFIELDCOND_H

#define BFIELDCOND_H


#include "EventPrimitives/EventPrimitives.h"

#include "CxxUtils/restrict.h"

#include <cmath>


class BFieldCond

{

public:

  // constructor

  BFieldCond(bool finite,

             const double* p1,

             const double* p2,

             double curr)

    : 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)

  {}


  // compute magnetic field, plus derivatives if requested, and add

  void addBiotSavart(double scaleFactor,

                     const double* ATH_RESTRICT xyz,

                     double* ATH_RESTRICT B,

                     double* ATH_RESTRICT deriv = nullptr) const;

  // scale the current wrt the nominal current

  void scaleCurrent(double factor) { m_curr = factor * m_nomCurr; }

  // accessors

  bool finite() const { return m_finite; }

  double p1(int i) const { return m_p1[i]; }

  double p2(int i) const { return m_p2[i]; }

  double curr() const { return m_curr; }


private:

  bool m_finite; // true if the conductor is finite in length


  /*

   * m_p1: One end of a finite conductor, or one point on an infinite conductor

   * m_p2: The other end of a finite conductor, or the direction vector of an

   * infinite conductor m_u : Direction vector (= m_p2 if infinite)

   */

  const Eigen::Vector3d m_p1, m_p2, m_u;

  double m_curr;    // current (in A) flowing through the conductor

  double m_nomCurr; // nominal current (in A) read from the map file

};

#endif