time_integration.h

#ifndef time_integration_h
#define time_integration_h
 
class timing
    {
public:
    inline timing(const double _tf, const double _dtmin, const double _dtmax)
        : tf(_tf), DTMIN(_dtmin), DTMAX(_dtmax), TAUR(100. * DTMAX), t(0)
        {
        set_dt(sqrt(DTMIN * DTMAX));
        }
 
    const double tf;
 
    const double DTMIN;  // 1e-14;
 
    const double DTMAX;  //  1e-5 en stat ;  1e-7 en dynamique;
 
    const double TAUR;
 
    double prefactor;
 
    inline double get_dt() const { return dt; }
 
    inline void set_dt(const double _dt)
        {
        dt = _dt;
        double t_tilde = _dt / TAUR;
        prefactor = (1. + t_tilde * abs(log( t_tilde)));
        }
 
    inline bool is_dt_TooSmall() const { return (dt < DTMIN); }
 
    inline void inc_t() { t += dt; }
 
    inline double get_t() const { return t; }
 
    inline void set_t(double _t) { t = _t; }
 
private:
    double t; 
    double dt; 
    };
 
#endif