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

#include <cmath>
#include <iostream>

#include"../util/ThreeVector.h"

//.............
// initialise  

void ThreeVector::initialise( float qx, float qy, float qz ) 
{
  px = qx ;
  py = qy ;
  pz = qz ;
}



//.................................
// To obtain the magnitude squared 

float ThreeVector::magnitudesq(  )
{
  return ( px*px + py*py + pz*pz ) ;
}



//.........................
// To obtain the magnitude 

float ThreeVector::magnitude( )
{
  return sqrt( magnitudesq( ) );
}


//.........................................
// To obtain the phin angle in the x-y plane

float ThreeVector::phi( )
{
  return acos( px / sqrt(px*px + py*py) ) ;
}



//........................................
// To take a dot product of two 3 vectors 

float ThreeVector::dotProduct( ThreeVector t2 )
{
  return ( px*t2.px + py*t2.py + pz*t2.pz ) ;
}


//....................................................
// To obtain the angle between two vectors in radians 

float ThreeVector::angle(  ThreeVector t2 )
{
  // Note: in this method we call other methods of this object itself
  // (the dotProduct and magnitude methods) as well as calling the magnitude method 
  // of the argument.
  float angle ;
  angle = dotProduct( t2 ) / magnitude( ) / t2.magnitude(  ) ;
  angle = acos(angle) ;
  return angle ;
}

//...................................
// To dump out the contents to cout

void ThreeVector::dump( )
  {
    std::cout << " The vector contents are " 
              << " px= " << px  
              << " py= " << py  
              << " pz= " << pz
              << std::endl ;
  }


//...............................................
// Default constructor

ThreeVector::ThreeVector( ) 
{
  px = 0 ;
  py = 0 ;
  pz = 0 ;
}

//.......................
// Constructor to set to some value

ThreeVector::ThreeVector( float qx, float qy, float qz ) 
{
  px = qx ;
  py = qy ;
  pz = qz ;
}

//.......................
// Constructor to set to specified magnitude, and define it to be in the x-y plane
// with the given value of phi in radians.

ThreeVector::ThreeVector( float mag, float phi ) 
{
  px = mag * cos( phi ) ;
  py = mag * sin( phi ) ;
  pz = 0. ;
}


//.......................
// Copy Constructor 

ThreeVector::ThreeVector( ThreeVector& src ) 
{
  px = src.px ;
  py = src.py ;
  pz = src.pz ;
}