// ----------------------------------------------------------------------------- D_MIN
double d_min(struct position pos, int level)
{
/*
Compute the minimal distance of the position pos to the "box"
(search space of the problem, global variable)
*/
int		d;
double	dmin;
double	md;
double	z;

dmin=fabs(pos.p.x[0]-problem[level].H.min[0]);

for (d=0;d<pos.p.size;d++)
{
	md=fabs(pos.p.x[d]-problem[level].H.min[d]);
	z=fabs(pos.p.x[d]-problem[level].H.max[d]);
	if (z<md) md=z;
	if(md<dmin) dmin=md;
}

return dmin;
}

// ----------------------------------------------------------------------------- DISTANCEdouble	distance(struct position pos1,struct position pos2){double 	d,dx;int		i;d=0;for (i=0;i<pos1.p.size;i++){	dx=pos1.p.x[i]-pos2.p.x[i];	d=d+dx*dx;}d=sqrt(d);return d;}// ----------------------------------------------------------------------------- ENERGY_Kdouble energy_k(int level){/*Compute the kinetic energy of the swarmThe tribe list TR is a global variable*/int      d;int      DD;double Ek;int      i;int      j;double vd;DD=TR[level].tr[0].part[0].x.p.size; Ek=0; for (i=0;i<TR[level].size;i++)  // For each tribe {      for (j=0;j<TR[level].tr[i].size;j++)  // for each particle in the tribe      {         for (d=0;d<DD;d++)  // Velocity component         {            vd= TR[level].tr[i].part[j].x.p.x[d]- TR[level].tr[i].part[j].prev_x.p.x[d] ;            Ek=Ek+vd*vd;         }      } }return Ek/2 ;}

// ----------------------------------------------------------------------------- ENERGY_P
double energy_p(int level)
{
/*
Compute the potential energy of the swarm
The tribe list TR and "problem" are global variable
*/
int      d;
int      DD;
double Ep;
int      i;
int      j;
double vd;

DD=TR[level].tr[0].part[0].x.p.size;

 Ep=0;
 for (i=0;i<TR[level].size;i++)  // For each tribe
 {
      for (j=0;j<TR[level].tr[i].size;j++)  // for each particle in the tribe
      {
		Ep=Ep+total_error(TR[level].tr[i].part[j].x.f);
      }

 }

return Ep/ problem[level].eps;
}
// ----------------------------------------------------------------------------- DISTANCES_PAIRSvoid distances_pairs(int level){/*    Histogram of distances between pairs of particules.  If they are random, it is "flat"    TO COMPLETE*/}// ----------------------------------------------------------------------------- INFORMATIVE_LINKSvoid informative_links (int level){ /* Compute some charactristics of the informative links graph: - diameter - aggregation coefficient etc. In particular, try to see if the graph is indeed a "small world".   TO COMPLETE */}