| /* |
| * Licensed to the Apache Software Foundation (ASF) under one |
| * or more contributor license agreements. See the NOTICE file |
| * distributed with this work for additional information |
| * regarding copyright ownership. The ASF licenses this file |
| * to you under the Apache License, Version 2.0 (the |
| * "License"); you may not use this file except in compliance |
| * with the License. You may obtain a copy of the License at |
| * |
| * http://www.apache.org/licenses/LICENSE-2.0 |
| * |
| * Unless required by applicable law or agreed to in writing, |
| * software distributed under the License is distributed on an |
| * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY |
| * KIND, either express or implied. See the License for the |
| * specific language governing permissions and limitations |
| * under the License. |
| */ |
| |
| package org.apache.iotdb.library.dprofile; |
| |
| import org.apache.iotdb.library.dprofile.util.CrossCorrelation; |
| import org.apache.iotdb.library.util.Util; |
| import org.apache.iotdb.udf.api.UDTF; |
| import org.apache.iotdb.udf.api.access.Row; |
| import org.apache.iotdb.udf.api.collector.PointCollector; |
| import org.apache.iotdb.udf.api.customizer.config.UDTFConfigurations; |
| import org.apache.iotdb.udf.api.customizer.parameter.UDFParameterValidator; |
| import org.apache.iotdb.udf.api.customizer.parameter.UDFParameters; |
| import org.apache.iotdb.udf.api.customizer.strategy.RowByRowAccessStrategy; |
| import org.apache.iotdb.udf.api.type.Type; |
| |
| import java.util.ArrayList; |
| |
| /** This function calculates auto-correlation factor of a single input series. */ |
| public class UDTFACF implements UDTF { |
| |
| private final ArrayList<Double> valueArrayList = new ArrayList<>(); |
| |
| @Override |
| public void validate(UDFParameterValidator validator) throws Exception { |
| validator |
| .validateInputSeriesNumber(1) |
| .validateInputSeriesDataType(0, Type.INT32, Type.INT64, Type.FLOAT, Type.DOUBLE); |
| } |
| |
| @Override |
| public void beforeStart(UDFParameters parameters, UDTFConfigurations configurations) |
| throws Exception { |
| configurations.setAccessStrategy(new RowByRowAccessStrategy()).setOutputDataType(Type.DOUBLE); |
| valueArrayList.clear(); |
| } |
| |
| @Override |
| public void transform(Row row, PointCollector collector) throws Exception { |
| if (row.isNull(0)) { |
| valueArrayList.add(Double.NaN); |
| } else { |
| valueArrayList.add(Util.getValueAsDouble(row, 0)); |
| } |
| } |
| |
| @Override |
| public void terminate(PointCollector collector) throws Exception { |
| ArrayList<Double> correlationArrayList = |
| CrossCorrelation.calculateCrossCorrelation(valueArrayList, valueArrayList); |
| for (int i = 0; i < correlationArrayList.size(); i++) { |
| collector.putDouble(i, correlationArrayList.get(i)); |
| } |
| } |
| |
| @Override |
| public void beforeDestroy() { |
| valueArrayList.clear(); |
| } |
| } |