Impala Documentation

template<class DstArrayT, class SrcArrayT>

double Impala::Core::Feature::WeibullNgbPnLoop< DstArrayT, SrcArrayT >::gammaFunc ( double xx ) const [inline]

Definition at line 259 of file WeibullNgbPnLoop.h.

00260     {
00261         double x,y,tmp,ser;
00262         static double cof[6] =
00263             {
00264                 76.18009172947146, -86.50532032941677,
00265                 24.01409824083091, -1.231739572450155,
00266                 0.1208650973866179e-2, -0.5395239384953e-5
00267             };
00268         
00269         int j;
00270         y=x=xx;
00271         tmp=x+5.5;
00272         tmp -= (x+0.5)*log(tmp);
00273         ser=1.000000000190015;
00274         for (j=0;j<=5;j++)
00275             ser += cof[j]/++y;
00276         xx = -tmp+log(2.5066282746310005*ser/x);
00277         return exp(xx);
00278     }