/* University College London Dept of Physics Course in C++ 3C59 
| all rights reserved 2000 
|
| Utility: DECLARATION of the ThreeVector class
|
|
| Author: P.Clarke 
*/

#ifndef  _threevec_h
#define  _threevec_h 1

#include <cmath>


class ThreeVector 
{

  private: 
    float px ; 
    float py ;
    float pz ;

  public:

  // To initialise the vector with 3 cartesian momentum components
  // Note:  this method should NOT be used after we have covered constructors
  void initialise( float px, float py, float pz ) ;

  // To return the square of the magnitude 
  float magnitudesq( ) ;

  // To return the magnitude 
  float magnitude( ) ;

  // To return the phi angle in the x-y plane 
  float phi( ) ;

  // To perform the dot product of two vectors 
  float dotProduct( ThreeVector t2 ) ;

  // To calculate the angle between two vectors in radians
  float angle( ThreeVector t2 ) ;

  // To dump out the contents to cout
  void dump( ) ;


  //.... these come later in the course......

  // Default constructor
  ThreeVector( ) ;

  // Constructor to set to specified x,y,z
  ThreeVector( float x, float y, float z ) ;

  // Constructor to set it to a specified magnitude and be in the x-y plane with the given phi
  ThreeVector( float magnitude, float phi ) ;

  // Copy constructor
  ThreeVector( ThreeVector& src ) ;

};

#endif