Impala Documentation

template<class HistT>

double Impala::Core::Histogram::FitWeibullMarginal< HistT >::gammaFunc ( double xx ) const [inline, private]

Definition at line 282 of file FitWeibullMarginal.h.

00283     {
00284         double x,y,tmp,ser;
00285         static double cof[6] =
00286             {
00287                 76.18009172947146, -86.50532032941677,
00288                 24.01409824083091, -1.231739572450155,
00289                 0.1208650973866179e-2, -0.5395239384953e-5
00290             };
00291         
00292         int j;
00293         y=x=xx;
00294         tmp=x+5.5;
00295         tmp -= (x+0.5)*log(tmp);
00296         ser=1.000000000190015;
00297         for (j=0;j<=5;j++)
00298             ser += cof[j]/++y;
00299         xx = -tmp+log(2.5066282746310005*ser/x);
00300         return exp(xx);
00301     }