public double pdf(double x){
  if (x < 0 || x > 1)   return 0.0;
  return Math.exp(PDF_CONST) * Math.pow(x,alpha - 1) * Math.pow(1 - x,beta - 1);
}

public double pdf ( double x ) { if ( x < 0 || x > 1 ) return 0.0 ; return Math . exp ( PDF_CONST ) * Math . pow ( x , alpha - 1 ) * Math . pow ( 1 - x , beta - 1 ) ; }
returns the cumulative distribution function .
