[iotdb] branch xianyi updated: add UDTFEn

[rong]

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rong pushed a commit to branch xianyi
in repository https://gitbox.apache.org/repos/asf/iotdb.git


The following commit(s) were added to refs/heads/xianyi by this push:
     new ea222e2  add UDTFEn
ea222e2 is described below

commit ea222e24b076786f0c051f8d11a1e0bf024a1ed1
Author: Steve Yurong Su <r...@apache.org>
AuthorDate: Mon Nov 22 16:06:14 2021 +0800

    add UDTFEn
---
 .../src/main/java/org/apache/iotdb/udf/UDTFEn.java | 55 ++++++++++++++++++++++
 1 file changed, 55 insertions(+)

diff --git a/example/udf/src/main/java/org/apache/iotdb/udf/UDTFEn.java 
b/example/udf/src/main/java/org/apache/iotdb/udf/UDTFEn.java
new file mode 100644
index 0000000..a3b166f
--- /dev/null
+++ b/example/udf/src/main/java/org/apache/iotdb/udf/UDTFEn.java
@@ -0,0 +1,55 @@
+/*
+ * 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.udf;
+
+import org.apache.iotdb.db.query.udf.api.UDTF;
+import org.apache.iotdb.db.query.udf.api.access.RowWindow;
+import org.apache.iotdb.db.query.udf.api.collector.PointCollector;
+import org.apache.iotdb.db.query.udf.api.customizer.config.UDTFConfigurations;
+import org.apache.iotdb.db.query.udf.api.customizer.parameter.UDFParameters;
+import 
org.apache.iotdb.db.query.udf.api.customizer.strategy.SlidingTimeWindowAccessStrategy;
+import org.apache.iotdb.tsfile.file.metadata.enums.TSDataType;
+
+import java.io.IOException;
+
+public class UDTFEn implements UDTF {
+
+  @Override
+  public void beforeStart(UDFParameters parameters, UDTFConfigurations 
configurations) {
+    configurations
+        .setAccessStrategy(new SlidingTimeWindowAccessStrategy("5m"))
+        .setOutputDataType(TSDataType.DOUBLE);
+  }
+
+  @Override
+  public void transform(RowWindow rowWindow, PointCollector collector) throws 
IOException {
+    int windowSize = rowWindow.windowSize();
+    if (windowSize != 30000) {
+      return;
+    }
+
+    double quadraticSum = 0;
+    for (int i = 0; i < windowSize; ++i) {
+      double raw = rowWindow.getRow(i).getDouble(0);
+      quadraticSum += raw * raw;
+    }
+    collector.putDouble(rowWindow.getRow(0).getTime(), quadraticSum / 
windowSize);
+  }
+}