public static double nextExpGamma(double shape,double scale,double bias){
  return nextExpGamma(shape,scale,bias,false);
}

public static double nextExpGamma ( double shape , double scale , double bias ) { return nextExpGamma ( shape , scale , bias , false ) ; }
sample from the gamma distribution , modified by a factor exp ( - ( x * bias ) ^ - 1 ) , i . e . from x ^ ( shape - 1 ) exp ( - x / scale ) exp ( - 1 / ( bias * x ) ) < p / > works by rejection sampling , using a shifted ordinary gamma as proposal distribution . < p / > ( for an older , less efficient algorithm that breaks down for shape < = 1 . 0 , see revision 287 )
