// Functions for three-vector class
// Glen Cowan, RHUL Physics Dept., 4 December 2001.

#include <iostream.h>
#include <math.h>
#include "ThreeVector.h"

ThreeVector::ThreeVector(){
  xVal = 0.;
  yVal = 0.;
  zVal = 0.;
}

ThreeVector::ThreeVector (float x, float y, float z){
  xVal = x;
  yVal = y;
  zVal = z;
}

float ThreeVector::x(){ return xVal; }
float ThreeVector::y(){ return yVal; }
float ThreeVector::z(){ return zVal; }

void ThreeVector::set(float x, float y, float z){
  xVal = x;
  yVal = y;
  zVal = z;
}

float ThreeVector::r(){
  float r2 = pow(xVal,2) + pow(yVal,2) + pow(zVal,2);
  float rVal = sqrt(r2);
  return rVal;
}

float ThreeVector::cosTheta(){
  float cosThetaVal = this->z()/this->r();
  return cosThetaVal;
}

float ThreeVector::theta(){
  float thetaVal = acos ( this->cosTheta() );
  return thetaVal;
}

float ThreeVector::rho(){
  float rhoVal = sqrt ( this->x()*this->x()  + this->y()*this->y() );
  return rhoVal;
}

float ThreeVector::cosPhi(){
   float cosPhiVal = this->x() / this->rho() ;
   return cosPhiVal;
}

float ThreeVector::sinPhi(){
  float sinPhiVal = this->y() / this->rho() ;
  return sinPhiVal;
}

float ThreeVector::phi(){
  float phiVal;
  const float pi = 3.14159265;
  if ( this->y() >=0 ) {
    phiVal = acos ( this->cosPhi() );
  }
  else {
    phiVal = acos ( - this->cosPhi() ) + pi ;
  }
  return phiVal;
}

float dotProd (ThreeVector a, ThreeVector b){
    float dot = a.x()*b.x()  +  a.y()*b.y()  +  a.z()*b.z();
    return dot;
}