code: public double valueAt( int col, int row ) {
          if (isInRaster(col, row)) {
              double value = iter.getSampleDouble(col, row, 0);
              return value;
          }
          return HMConstants.doubleNovalue;
      }
docs: Get the raster value at a given col/row.
  
  @param col
  @param row
  @return the value.