#include "My3Vector.h"
#include <iostream>
#include <cmath>

 // implementation
 
 My3Vector::My3Vector() { // default constructor
   x = 0.; y = 0.; z = 0.; // set coords to 0.
 }
 My3Vector::My3Vector( double xv, double yv, double zv ) {
   x = xv; y = yv; z = zv; // take args for coords
 }
 // get length of vector
 double My3Vector::Length(){  
   return( sqrt( x*x + y*y +z*z ) );
 }
 // access elements
 double My3Vector::X() { return x; }
 double My3Vector::Y() { return y; }
 double My3Vector::Z() { return z; }
 // add
 My3Vector My3Vector::Add(  My3Vector & p ) {
   My3Vector t; 
   t.x = x + p.x;   t.y = y + p.y;   t.z = z + p.z;
   return( t );
 } 

void My3Vector::Print( ) {
  std::cout << "( " << x << ", " << y << ", " << z << " )" << std::endl;
}


double My3Vector::Dot(My3Vector & v) 
{
  return( x*v.x + y*v.y + z*v.z );
}

double My3Vector::Angle(My3Vector & v) 
{
  double ltot = Length()*v.Length();
  if( ltot <= 0) {
    return 0.0;
  }
  else{
    double arg = Dot(v)/ltot;
    if(arg >  1.0) arg =  1.0;
    if(arg < -1.0) arg = -1.0;
    return acos(arg)*180./M_PI;
  }
}