AnimaL

Tutorial

Documentation

---

Documentation

• Overview
• Modules
• Namespace List
• Class Hierarchy
• Alphabetical List
• Compound List
• File List
• Namespace Members
• Compound Members
• File Members
• Examples

---

odeSolver.h

Go to the documentation of this file.

#ifndef OdeSolver_h_________________________________
#define OdeSolver_h_________________________________

#include <animal/integrator.h>

namespace animal {

template<
    class t_Positions,
    class t_Vector,
    class t_Real>
class OdeSolver
{
public:
    typedef t_Positions Positions;  
    typedef t_Vector Vector; 
    typedef t_Real Real;     
  static const int EULER          = 0; 
  static const int RK2            = 1; 
  static const int RK4            = 2; 
  static const int MODMID         = 3; 
  static const int VVERLET        = 4; 

    OdeSolver();

    virtual ~OdeSolver(){}
    
    virtual void solveODE( Positions& pos, Vector& vel, Real dt );

    void setMethod( int m );
    
    int method() const;

    void setMMIDsteps( int n ){ _MMIDsteps = n; }

    int MMIDsteps() const { return _MMIDsteps; }

    int _method;  
    int _MMIDsteps;      
protected:
    
    virtual void computeAccelerations( Vector& acceleration, const Positions& pos, const Vector& vel )=0;
    

    typedef Derivs<Vector,Vector> Der;  
    
    Vector dv1;  
    Vector da1;  
    Der d1; 
    
    Vector dv2;  
    Vector da2;  
    Der d2; 
    
    Vector dv3;  
    Vector da3;  
    Der d3; 
    
    Vector dv4;  
    Vector da4;  
    Der d4; 
    
    
    typedef States<Positions,Vector> Sta;  

    Positions sp1;   
    Vector sv1;   
    Sta s1;        

    Positions sp2;   
    Vector sv2;   
    Sta s2;        

    Positions sp3;   
    Vector sv3;   
    Sta s3;        

    Vector velHalf;  // auxilliary variable for half step velocities - used in velocity verlet scheme

    void computeDerivative( Der& d, const Sta& s, Real );

    void euler(Positions& pos, Vector& vel, Real h, Real t=0);

    void rk2(Positions& pos, Vector& vel, Real h, Real t=0);

    void rk4(Positions& pos, Vector& vel, Real h, Real t=0);

    void modmid(Positions& pos, Vector& vel, Real h, int n, Real t=0);

    // velocity verlet scheme
    void velocityVerlet(Positions& pos, Vector& vel, Real h);

    //=======================================================================
    // The following methods perform time integration given initial conditions and all necessary auxiliary containers

    void integrate_euler
    (
        Sta& s,
        Real h,
        Real t,
        Der& d
    );
    
    void integrate_rk2
    ( 
        Sta& s, 
        Real h, 
        Real t,
        Der& d, 
        Sta& s1 
    );
    
    void integrate_rk4
    (
        Sta& s,
        Real h,
        Real t,
        Der& d1,
        Der& d2,
        Der& d3,
        Der& d4,
        Sta& s1
    );

    void integrate_modmid
    (
        Sta& s,
        Real h,
        Real t,
        int n,
        Der& d1,
        Sta& s1,
        Sta& s2,
        Sta& s3
    );

     // perform velocity verlet integration on given states
    void integrate_VVerlet(
        Sta& s,
        Real h,
        Der& d  );


};
}//animal


#endif

---