public static String formatNumber(double value){
  if (Double.isNaN(value)) {
    return "?";
  }
  return formatNumber(value,numberOfFractionDigits,false);
}

public static String formatNumber ( double value ) { if ( Double . isNaN ( value ) ) { return "?" ; } return formatNumber ( value , numberOfFractionDigits , false ) ; }
returns a formatted string of the given number ( number format with usually three fraction digits ) .
