#include <stdio.h> 
#include <math.h>

struct Par {
		double s;
		double s2;
		double r2;
		double r;} a;
 
void takens(int n, double v[], double dv[], double t)
/* Takens equations */
{
double x,y,z,w,rhox, rhoy, rhoz, rhow;
x=v[0]; y=v[1]; z=v[2]; w=v[3];



 dv[0]= (1.0/1.0)*(-x+1/(1+exp(-1*(a.r+10*x-10*y)))) ;
 dv[1]=         1*(-y+1/(1+exp(-1*(a.s+10.*x+2*y))));
 dv[2]= (1.0/1.0)*(-z+1/(1+exp(-1*(a.r2+10*z-10*w))));
 dv[3]=         1*(-w+1/(1+exp(-1*(a.s2+10.*z+2*w))));

 

return;
}




void main()
{
FILE *ptr;
int n_it,n_pre,i;
double v[4],t,dt,t_pre;

ptr=fopen("results1.dat","wt");

a.s=-6.0;
a.r=-0.2;



v[0]=0.51; v[1]=0.5;
v[2]=0.551; v[3]=0.5;

dt=0.01; t_pre=1000; 
t_pre=0;
t=180; 


i=0; 

while(t>0)
{


a.r2=a.r+5*(0.01*v[0]-0.02*v[1]);
a.s2=a.s+5*(0.01*v[0]-0.03*v[1]);
rk4(takens,v,4,t,dt);
if(t<80) fprintf(ptr,"%lg\t%lg\t%lg\t%lg\n",v[0],v[1],v[2]+1,v[3]);
t-=dt;
t_pre-=dt;



}


	fclose(ptr);

exit(0);
}