#include <math.h>float gammln(float xx){  double x,tmp,ser;  static double cof[6]={76.18009173,-86.50532033,24.01409822,			-1.231739516,0.120858003e-2,-0.536382e-5};  int j;    x=xx-1.0;  tmp=x+5.5;  tmp -= (x+0.5)*log(tmp);  ser=1.0;  for (j=0;j<=5;j++) {    x += 1.0;    ser += cof[j]/x;  }  return -tmp+log(2.50662827465*ser);}