static double
upper_tail (const unsigned int k, const unsigned int n1,
const unsigned int n2, const unsigned int t)
{
double relerr;
unsigned int i = k + 1;
double s, Q;
s = gsl_ran_hypergeometric_pdf (i, n1, n2, t);
Q = s;
while (i < t)
{
double factor =
((n1 - i) / (i + 1.0)) * ((t - i) / (n2 + i + 1.0 - t));
s *= factor;
Q += s;
relerr = s / Q;
if (relerr < GSL_DBL_EPSILON)
break;
i++;
}
return Q;
}
static double
lower_tail (const unsigned int k, const unsigned int n1,
const unsigned int n2, const unsigned int t)
{
double relerr;
int i = k;
double s, P;
s = gsl_ran_hypergeometric_pdf (i, n1, n2, t);
P = s;
while (i > 0)
{
double factor =
(i / (n1 - i + 1.0)) * ((n2 + i - t) / (t - i + 1.0));
s *= factor;
P += s;
relerr = s / P;
if (relerr < GSL_DBL_EPSILON)
break;
i--;
}
return P;
}
double calculate_S( vector< struct cnfo >* cluster_info, int ne, int nv ){
unsigned int F = ( nv * ( nv - 1 ) ) / 2;
unsigned int n = ne;
unsigned int M = 0;
unsigned int p = 0;
for( unsigned int i = 0; i < cluster_info->size(); i++ ){
unsigned int temp = cluster_info->at(i).value1;
M = M + ( ( temp ) * ( temp - 1 ) / 2 );
p = p + cluster_info->at(i).value3;
}
// printf("%d\t%d\n", M, n);
unsigned int upper_limit = min( M , n );
// printf("%d\n", upper_limit);
double surprise = 0.0;
// printf(" Stats:\n ");
// printf("\tM:%d\tp:%d\tF-M:%d\tn:%d\n", M, p, F-M, n);
int i = p;
do{
surprise += gsl_ran_hypergeometric_pdf( i, M, ( F - M ), n );
// surprise += gsl_cdf_hypergeometric_P( i, M, (F-M), n );
// printf("%lf\n", surprise );
p = p + 1;
}
while( p < upper_limit );
// printf("\tcalcS: %lf \n", surprise );
// surprise = gsl_sf_log( surprise );
return surprise;
}
double
test_hypergeometric6_pdf (unsigned int n)
{
return gsl_ran_hypergeometric_pdf (n, 2, 10, 3);
}
double
test_hypergeometric5_pdf (unsigned int n)
{
return gsl_ran_hypergeometric_pdf (n, 2, 7, 5);
}
double
test_hypergeometric4_pdf (unsigned int n)
{
return gsl_ran_hypergeometric_pdf (n, 5, 7, 20);
}