code: public double getDoubleValueFromMap( RandomIter map ) {
          try {
              if (map == null) {
                  return HMConstants.doubleNovalue;
              }
              double value = map.getSampleDouble(col, row, 0);
              return value;
          } catch (Exception e) {
              // ignore and return novalue
              return HMConstants.doubleNovalue;
          }
      }
docs: Get the double value of another map in the current node position.
  
  @param map the map from which to get the value.
  @return the double value or a novalue.