odesolve.h Source File

00001 /*
00002     Dynamics/Kinematics modeling and simulation library.
00003     Copyright (C) 1999 by Michael Alexander Ewert
00004 
00005     This library is free software; you can redistribute it and/or
00006     modify it under the terms of the GNU Library General Public
00007     License as published by the Free Software Foundation; either
00008     version 2 of the License, or (at your option) any later version.
00009 
00010     This library is distributed in the hope that it will be useful,
00011     but WITHOUT ANY WARRANTY; without even the implied warranty of
00012     MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
00013     Library General Public License for more details.
00014 
00015     You should have received a copy of the GNU Library General Public
00016     License along with this library; if not, write to the Free
00017     Software Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
00018 
00019 */
00020 #ifndef __CTODESOLVER_H__
00021 #define __CTODESOLVER_H__
00022 
00023 // this code was adapted from an ode solver by Brian Mirtich
00024 
00025 #include <assert.h>
00026 #include "csphyzik/phyztype.h"
00027 
00028 #define ODE_INITIAL_STATE_SIZE  1024
00029 
00030 
00031 typedef void (*dydt_function)(real t, const real statev[],  real delta_statev[] );
00032 
00033 
00034 // virtual base-class on which concrete ode solver algorithms are built
00035 // NOTE: don't derive any classes from any classes derived from this one.
00036 class OdeSolver
00037 {
00038 public:
00039 
00040   OdeSolver();
00041   virtual ~OdeSolver();
00042 
00047   virtual void calc_step (real y0[], real y1[], unsigned int len,
00048                           real t0, real t1, dydt_function dydt) = 0;
00049 
00050 protected:
00051 
00052   virtual void ode_realloc (int new_size);
00053 
00055   unsigned int state_size;
00056 
00058   real *dy;
00059   real *Iy;
00060 };
00061 
00067 class OdeRungaKutta4 : public OdeSolver
00068 {
00069 public:
00070 
00071   OdeRungaKutta4 ();
00072   virtual ~OdeRungaKutta4 ();
00073 
00074   void calc_step (real y0[], real y1[], unsigned int len,
00075                   real t0, real t1, dydt_function dydt);
00076 
00077 private:
00078 
00079   void ode_realloc (int new_size);
00080 
00082   real *k1;
00083   real *k2;
00084   real *k3;
00085   real *k4;
00086 };
00087 
00093 class OdeEuler : public OdeSolver
00094 {
00095 public:
00096 
00097   OdeEuler ();
00098 
00099   void calc_step (real y0[], real y1[], unsigned int len,
00100                   real t0, real t1, dydt_function dydt);
00101 
00102 };
00103 
00104 
00111 class OdeMidPoint : public OdeSolver
00112 {
00113 public:
00114 
00115   OdeMidPoint();
00116 
00117   void calc_step (real y0[], real y1[], unsigned int len,
00118                   real t0, real t1, dydt_function dydt);
00119 
00120 };
00121 
00122 #endif // __CTODESOLVER_H__