/* This program integrates the Lorenz II system */ 
# include "easynum.c" /* http://staff.vscht.cz/~pokornp/easynum/ */
/************************************/
void lorenz2 (time,xyz,pars, xyzdot,g,J,dim)
 real time;
 vector xyz,pars,xyzdot,g;
 matrix J; 
 int dim;
{
 real  a = 0.25, b = 4.0, F = 8.0, G = 1.0,
  x = xyz[0], y = xyz[1], z = xyz[2];

 xyzdot[0] = -y*y-z*z-a*(x-F);
 xyzdot[1] = x*y-b*x*z-y+G;
 xyzdot[2] = b*x*y+x*z-z;

} /* lorenz2 */
/************************************/
int main ()
{
 real t  = 0,          /* time */ 
      Ts = 0.1;        /* sampling period */
 vector xyz,pars;      /* state vector and parameters */
 int i,imax=10000,dim=3;
 
 xyz[0] =  1.1;          /* set initial conditions */
 xyz[1] =  0.3;
 xyz[2] =  2.1;

 for (i=0;i<imax;i++) {
  integdt (&t,Ts,xyz,lorenz2,pars,dim);  /* integrate lorenz for time Ts */
  printf ("%G %G %G %G\n",t,xyz[0],xyz[1],xyz[2]);
 };
 return (0);
} /* main */
/************************************/