Schema_Euler_Semi_Implicite.h

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#ifndef Schema_Euler_Semi_Implicite_included
#define Schema_Euler_Semi_Implicite_included
 
/*! @brief class Schema_Euler_Semi_Implicite Il herite de schema Euler implicite et porte un solveur, linéaire ou non linéaire.
 *  Le principe repose sur une interpolation temporelle (schéma theta) des champs entre les pas de temps n et n+1.
 *  Pour un champ u(n), on écrit : u(n+theta) = theta * u(n+1) + (1-theta) * u(n)
 *  Si theta = 1, on a bien un schéma entièrement implicite, si theta = 0, schema explicite (ATTENTION CEPENDANT à la valeur theta=0).
 *   introduit un coefficient theta d'interpolation temporelle
 * @sa Schema_Euler_Implicite
 *
 */
 
#include <Schema_Euler_Implicite.h>
#include <Equation_base.h>
#include <Probleme_base.h>
 
class Schema_Euler_Semi_Implicite : public Schema_Euler_Implicite
{
 
  Declare_instanciable(Schema_Euler_Semi_Implicite);
 
public :
 
  void set_param(Param& )const override;
 
  // Spécifique à notre schéma theta
  inline double temps_intermediaire() const { return temps_courant() + theta_*pas_de_temps(); }
 
  int faire_un_pas_de_temps_pb_couple(Probleme_Couple&, int& ok) override;
  int faire_un_pas_de_temps_eqn_base(Equation_base&) override;
 
  // Spécificité du schéma semi-implicite
  inline double coeff_theta() const { return theta_; }
  bool is_explicit();
 
protected:
  double theta_=-123.; // Coefficient d'interpolation temporelle entre l'instant n et l'instant n+1
};
 
#endif