protected double compute(String value){
  if (value != null) {
    try {
      return Double.parseDouble(value);
    }
 catch (    NumberFormatException e) {
      if (POSITIVE_INFINITY_STRING.equals(value)) {
        return Double.POSITIVE_INFINITY;
      }
 else       if (NEGATIVE_INFINITY_STRING.equals(value)) {
        return Double.NEGATIVE_INFINITY;
      }
      return Double.NaN;
    }
  }
  return Double.NaN;
}

protected double compute ( String value ) { if ( value != null ) { try { return Double . parseDouble ( value ) ; } catch ( NumberFormatException e ) { if ( POSITIVE_INFINITY_STRING . equals ( value ) ) { return Double . POSITIVE_INFINITY ; } else if ( NEGATIVE_INFINITY_STRING . equals ( value ) ) { return Double . NEGATIVE_INFINITY ; } return Double . NaN ; } } return Double . NaN ; }
computes the result for one input string value .
