#ifndef _SUN_H_
#define _SUN_H_

#include <math.h>

class Sun
{
  public:
    Sun(float latitude0): latitude(latitude0){};
    Sun(){};
    
    void setlatitude(float latitude0){latitude=latitude0;};
    
    float declination(int day) {return 23.4*sin(2*M_PI*(284+day)/365);}
    float hourangle(int time) {return 15*(time-12);}
    float elevationangle(int day, int time) {
      return asin(sin(declination(day)*M_PI/180)*
             sin(latitude*M_PI/180)*
             cos(hourangle(time)*M_PI/180)*
             cos(declination(day)*M_PI/180)*
             cos(latitude*M_PI/180))
             *180/M_PI;
    }
    float azimutangle(int day, int time){
      float tau, sin_tau, cos_tau, sin_phi, cos_phi, tan_dec;

      tan_dec = tan(declination(day)*M_PI/180);
      tau = hourangle(time)*M_PI/180;
      sin_tau = sin(tau);
      cos_tau = cos(tau);
      sin_phi = sin(latitude*M_PI/180);
      cos_phi = cos(latitude*M_PI/180);
      
      return atan2(sin_tau, cos_tau*sin_phi-tan_dec*cos_phi)/180*M_PI;      
    }
  private:
    float latitude;
};

#endif /* _SUN_H_ */