double calculate_rho()
{
int nr_free1 = 0,nr_free2 = 0;
double ub1 = INF, ub2 = INF;
double lb1 = -INF, lb2 = -INF;
double sum_free1 = 0, sum_free2 = 0;
for(int i=0;i<active_size;i++)
{
if(y[i]==+1)
{
if(is_lower_bound(i))
ub1 = Math.min(ub1,G[i]);
else if(is_upper_bound(i))
lb1 = Math.max(lb1,G[i]);
else
{
++nr_free1;
sum_free1 += G[i];
}
}
else
{
if(is_lower_bound(i))
ub2 = Math.min(ub2,G[i]);
else if(is_upper_bound(i))
lb2 = Math.max(lb2,G[i]);
else
{
++nr_free2;
sum_free2 += G[i];
}
}
}
double r1,r2;
if(nr_free1 > 0)
r1 = sum_free1/nr_free1;
else
r1 = (ub1+lb1)/2;
if(nr_free2 > 0)
r2 = sum_free2/nr_free2;
else
r2 = (ub2+lb2)/2;
si.r = (r1+r2)/2;
return (r1-r2)/2;
}
