Polar3D.h

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// @(#)root/mathcore:$Id$
// Authors: W. Brown, M. Fischler, L. Moneta    2005
 
/**********************************************************************
 *                                                                    *
 * Copyright (c) 2005 , LCG ROOT MathLib Team  and                    *
 *                      FNAL LCG ROOT MathLib Team                    *
 *                                                                    *
 *                                                                    *
 **********************************************************************/
 
// Header file for class Polar3D
//
// Created by: Lorenzo Moneta  at Mon May 30 11:40:03 2005
// Major revamp:  M. Fischler  at Wed Jun  8 2005
//
// Last update: $Id$
//
#ifndef ROOT_MathX_GenVectorX_Polar3D
#define ROOT_MathX_GenVectorX_Polar3D 1
 
#include "Math/Math.h"
 
#include "MathX/GenVectorX/eta.h"
 
#include "MathX/GenVectorX/MathHeaders.h"
 
#include "MathX/GenVectorX/AccHeaders.h"
 
using namespace ROOT::ROOT_MATH_ARCH;
 
#include <cmath>
 
namespace ROOT {
 
namespace ROOT_MATH_ARCH {
 
//__________________________________________________________________________________________
/**
    Class describing a polar coordinate system based on r, theta and phi
    Phi is restricted to be in the range [-PI,PI)
 
    @ingroup GenVectorX
 
    @see GenVectorX
*/
 
template <class T>
class Polar3D {
 
public:
   typedef T Scalar;
 
   /**
      Default constructor with r=theta=phi=0
   */
   constexpr Polar3D() noexcept = default;
 
   /**
      Construct from the polar coordinates:  r, theta and phi
   */
   constexpr Polar3D(T r, T theta, T phi) noexcept : fR(r), fTheta(theta), fPhi(phi) { Restrict(); }
 
   /**
      Construct from any Vector or coordinate system implementing
      R(), Theta() and Phi()
   */
   template <class CoordSystem>
   explicit Polar3D(const CoordSystem &v) : fR(v.R()), fTheta(v.Theta()), fPhi(v.Phi())
   {
      Restrict();
   }
 
   /**
      Set internal data based on an array of 3 Scalar numbers
   */
   void SetCoordinates(const Scalar src[])
   {
      fR = src[0];
      fTheta = src[1];
      fPhi = src[2];
      Restrict();
   }
 
   /**
      get internal data into an array of 3 Scalar numbers
   */
   void GetCoordinates(Scalar dest[]) const
   {
      dest[0] = fR;
      dest[1] = fTheta;
      dest[2] = fPhi;
   }
 
   /**
      Set internal data based on 3 Scalar numbers
   */
   void SetCoordinates(Scalar r, Scalar theta, Scalar phi)
   {
      fR = r;
      fTheta = theta;
      fPhi = phi;
      Restrict();
   }
 
   /**
      get internal data into 3 Scalar numbers
   */
   void GetCoordinates(Scalar &r, Scalar &theta, Scalar &phi) const
   {
      r = fR;
      theta = fTheta;
      phi = fPhi;
   }
 
   Scalar R() const { return fR; }
   Scalar Phi() const { return fPhi; }
   Scalar Theta() const { return fTheta; }
   Scalar Rho() const { return fR * math_sin(fTheta); }
   Scalar X() const { return Rho() * math_cos(fPhi); }
   Scalar Y() const { return Rho() * math_sin(fPhi); }
   Scalar Z() const { return fR * math_cos(fTheta); }
   Scalar Mag2() const { return fR * fR; }
   Scalar Perp2() const { return Rho() * Rho(); }
 
   // pseudorapidity
   Scalar Eta() const { return Impl::Eta_FromTheta(fTheta, fR); }
 
   // setters (only for data members)
 
   /**
       set the r coordinate value keeping theta and phi constant
   */
   void SetR(const T &r) { fR = r; }
 
   /**
       set the theta coordinate value keeping r and phi constant
   */
   void SetTheta(const T &theta) { fTheta = theta; }
 
   /**
       set the phi coordinate value keeping r and theta constant
   */
   void SetPhi(const T &phi)
   {
      fPhi = phi;
      Restrict();
   }
 
   /**
       set all values using cartesian coordinates
   */
   void SetXYZ(Scalar x, Scalar y, Scalar z);
 
private:
   inline static Scalar pi() { return M_PI; }
   inline void Restrict()
   {
      if (fPhi <= -pi() || fPhi > pi())
         fPhi = fPhi - math_floor(fPhi / (2 * pi()) + .5) * 2 * pi();
   }
 
public:
   /**
       scale by a scalar quantity - for polar coordinates r changes
   */
   void Scale(T a)
   {
      if (a < 0) {
         Negate();
         a = -a;
      }
      // angles do not change when scaling by a positive quantity
      fR *= a;
   }
 
   /**
      negate the vector
   */
   void Negate()
   {
      fPhi = (fPhi > 0 ? fPhi - pi() : fPhi + pi());
      fTheta = pi() - fTheta;
   }
 
   // assignment operators
   /**
      generic assignment operator from any coordinate system
   */
   template <class CoordSystem>
   Polar3D &operator=(const CoordSystem &c)
   {
      fR = c.R();
      fTheta = c.Theta();
      fPhi = c.Phi();
      return *this;
   }
 
   /**
      Exact equality
   */
   bool operator==(const Polar3D &rhs) const { return fR == rhs.fR && fTheta == rhs.fTheta && fPhi == rhs.fPhi; }
   bool operator!=(const Polar3D &rhs) const { return !(operator==(rhs)); }
 
   // ============= Compatibility section ==================
 
   // The following make this coordinate system look enough like a CLHEP
   // vector that an assignment member template can work with either
   T x() const { return X(); }
   T y() const { return Y(); }
   T z() const { return Z(); }
 
   // ============= Specializations for improved speed ==================
 
   // (none)
 
#if defined(__MAKECINT__) || defined(G__DICTIONARY)
 
   // ====== Set member functions for coordinates in other systems =======
 
   void SetX(Scalar x);
 
   void SetY(Scalar y);
 
   void SetZ(Scalar z);
 
   void SetRho(Scalar rho);
 
   void SetEta(Scalar eta);
 
#endif
 
private:
   T fR = 0;
   T fTheta = 0;
   T fPhi = 0;
};
 
} // end namespace ROOT_MATH_ARCH
 
} // end namespace ROOT
 
// move implementations here to avoid circle dependencies
 
#include "MathX/GenVectorX/Cartesian3D.h"
 
#if defined(__MAKECINT__) || defined(G__DICTIONARY)
#include "MathX/GenVectorX/GenVector_exception.h"
#include "MathX/GenVectorX/CylindricalEta3D.h"
#endif
 
namespace ROOT {
 
namespace ROOT_MATH_ARCH {
 
template <class T>
void Polar3D<T>::SetXYZ(Scalar xx, Scalar yy, Scalar zz)
{
   *this = Cartesian3D<Scalar>(xx, yy, zz);
}
 
#if defined(__MAKECINT__) || defined(G__DICTIONARY)
#if !defined(ROOT_MATH_SYCL) && !defined(ROOT_MATH_CUDA)
// ====== Set member functions for coordinates in other systems =======
 
template <class T>
void Polar3D<T>::SetX(Scalar xx)
{
   GenVector_exception e("Polar3D::SetX() is not supposed to be called");
   throw e;
   Cartesian3D<Scalar> v(*this);
   v.SetX(xx);
   *this = Polar3D<Scalar>(v);
}
template <class T>
void Polar3D<T>::SetY(Scalar yy)
{
   GenVector_exception e("Polar3D::SetY() is not supposed to be called");
   throw e;
   Cartesian3D<Scalar> v(*this);
   v.SetY(yy);
   *this = Polar3D<Scalar>(v);
}
template <class T>
void Polar3D<T>::SetZ(Scalar zz)
{
   GenVector_exception e("Polar3D::SetZ() is not supposed to be called");
   throw e;
   Cartesian3D<Scalar> v(*this);
   v.SetZ(zz);
   *this = Polar3D<Scalar>(v);
}
template <class T>
void Polar3D<T>::SetRho(Scalar rho)
{
   GenVector_exception e("Polar3D::SetRho() is not supposed to be called");
   throw e;
   CylindricalEta3D<Scalar> v(*this);
   v.SetRho(rho);
   *this = Polar3D<Scalar>(v);
}
template <class T>
void Polar3D<T>::SetEta(Scalar eta)
{
   GenVector_exception e("Polar3D::SetEta() is not supposed to be called");
   throw e;
   CylindricalEta3D<Scalar> v(*this);
   v.SetEta(eta);
   *this = Polar3D<Scalar>(v);
}
 
#endif
#endif
 
} // end namespace ROOT_MATH_ARCH
 
} // end namespace ROOT
 
#endif /* ROOT_MathX_GenVectorX_Polar3D  */