class ROOT::Math::LorentzVector<ROOT::Math::PxPyPzM4D<double> >

 ------ assignment ------

          Assignment operator from a lorentz vector of arbitrary type

 ------ Set, Get, and access coordinate data ------

          Retrieve a const reference to  the coordinates object

          Set internal data based on an array of 4 Scalar numbers

          get internal data into 4 Scalar numbers

          get internal data into an array of 4 Scalar numbers

 ------------------- Equality -----------------

          Exact equality

 ------ Individual element access, in various coordinate systems ------
 individual coordinate accessors in various coordinate systems

          spatial X component

          spatial Y component

          spatial Z component

          return 4-th component (time, or energy for a 4-momentum vector)

          return magnitude (mass) squared  M2 = T**2 - X**2 - Y**2 - Z**2
          (we use -,-,-,+ metric)

          return magnitude (mass) using the  (-,-,-,+)  metric.
          If M2 is negative (space-like vector) a GenVector_exception
          is suggested and if continuing, - sqrt( -M2) is returned

          return the spatial (3D) magnitude ( sqrt(X**2 + Y**2 + Z**2) )

          return the square of the spatial (3D) magnitude ( X**2 + Y**2 + Z**2 )

          return the square of the transverse spatial component ( X**2 + Y**2 )

          return the  transverse spatial component sqrt ( X**2 + Y**2 )

          return the transverse mass squared
          \f[ m_t^2 = E^2 - p{_z}^2 \f]

          return the transverse mass
          \f[ \sqrt{ m_t^2 = E^2 - p{_z}^2} X sign(E^ - p{_z}^2) \f]

          return the transverse energy squared
          \f[ e_t = \frac{E^2 p_{\perp}^2 }{ |p|^2 } \f]

          return the transverse energy
          \f[ e_t = \sqrt{ \frac{E^2 p_{\perp}^2 }{ |p|^2 } } X sign(E) \f]

          azimuthal  Angle

          polar Angle

          pseudorapidity
          \f[ \eta = - \ln { \tan { \frac { \theta} {2} } } \f]

LorentzVector<CoordinateType> v(*this);
v.Negate();

 ---- Relativistic Properties ----

          Rapidity relative to the Z axis:  .5 log [(E+Pz)/(E-Pz)]

          Rapidity in the direction of travel: atanh (|P|/E)=.5 log[(E+P)/(E-P)]

          Determine if momentum-energy can represent a physical massive particle

          Determine if momentum-energy can represent a massless particle

          Determine if momentum-energy is spacelike, and represents a tachyon

          The beta vector for the boost that would bring this vector into
          its center of mass frame (zero momentum)

 TODO - should attempt to Throw with msg about
 boostVector computed for LorentzVector with t=0

beta and gamma

           Return beta scalar value

           Return Gamma scalar value

 Method providing limited backward name compatibility with CLHEP ----

 Methods  requested by CMS ---

          Methods setting a Single-component
          Work only if the component is one of which the vector is represented.
          For example SetE will work for a PxPyPzE Vector but not for a PxPyPzM Vector.