@Override
  public void transform(Row row, PointCollector pc) throws Exception {
    switch (dataType) {
      case INT32:
        transformInt(row);
        break;
      case INT64:
        transformLong(row);
        break;
      case FLOAT:
        transformFloat(row);
        break;
      case DOUBLE:
        transformDouble(row);
        break;
      case BLOB:
      case TIMESTAMP:
      case BOOLEAN:
      case STRING:
      case TEXT:
      case DATE:
      default:
        break;
    }
  }
This function is used to calculate the spread of time series, that is, the maximum value minus
the minimum value.
library-udf/src/main/java/org/apache/iotdb/library/dprofile/UDAFSpread.java