@Override
  public void terminate(PointCollector pointCollector) throws Exception {
    if (!s.equals("") || !method.equals("")) { // When user offers at least one parameter
      DWTUtil transformer = new DWTUtil(method, s, layer, value);
      transformer.waveletTransform();
      double[] r = transformer.getData();
      for (int i = 0; i < r.length; i++) {
        pointCollector.putDouble(timestamp.get(i), r[i]);
      }
    }
  }
This function calculates discrete wavelet transform of an input series. Input series must be an
integer exponent of 2. Input series is treated as sampled in equal distances.
library-udf/src/main/java/org/apache/iotdb/library/frequency/UDTFDWT.java