(iotdb) 06/31: add

[le...@apache.org]

This is an automated email from the ASF dual-hosted git repository.

leirui pushed a commit to branch research/LTS-visualization
in repository https://gitbox.apache.org/repos/asf/iotdb.git

commit 8e34afa43f638ed22c9008fb87abf812a6574cc7
Author: Lei Rui <10...@qq.com>
AuthorDate: Sun Sep 29 00:06:57 2024 +0800

    add
---
 .../db/query/simpiece/MySample_fsw_motivation.java | 109 +++++++++++++++++++++
 1 file changed, 109 insertions(+)

diff --git a/server/src/main/java/org/apache/iotdb/db/query/simpiece/MySample_fsw_motivation.java b/server/src/main/java/org/apache/iotdb/db/query/simpiece/MySample_fsw_motivation.java
new file mode 100644
index 00000000000..d0c738e04d6
--- /dev/null
+++ b/server/src/main/java/org/apache/iotdb/db/query/simpiece/MySample_fsw_motivation.java
@@ -0,0 +1,109 @@
+/*
+ * 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.
+ */
+
+// Sim-Piece code forked from https://github.com/xkitsios/Sim-Piece.git
+
+package org.apache.iotdb.db.query.simpiece;
+
+import java.io.FileInputStream;
+import java.io.FileWriter;
+import java.io.IOException;
+import java.io.PrintWriter;
+import java.util.List;
+
+public class MySample_fsw_motivation {
+
+  public static void main(String[] args) {
+    String file = "tmp.csv";
+    String out = "tmp-fsw.csv";
+    int[] noutList = new int[]{7};
+    double[] epsilonList = new double[]{3.342602252960205};
+
+    for (int nout : noutList) {
+      boolean hasHeader = false;
+      try (FileInputStream inputStream = new FileInputStream(file)) {
+        String delimiter = ",";
+        TimeSeries ts =
+            TimeSeriesReader.getMyTimeSeries(
+                inputStream, delimiter, false, -1, 0, hasHeader, false);
+//        double epsilon = getFSWParam(nout, ts, 1e-6);
+        double epsilon = epsilonList[0];
+        List<Point> reducedPoints = FSW.reducePoints(ts.data, epsilon);
+        System.out.println(
+            "epsilon="
+                + epsilon
+                + ",actual m="
+                + reducedPoints.size());
+        try (PrintWriter writer = new PrintWriter(new FileWriter(out))) {
+          for (Point p : reducedPoints) {
+            writer.println(p.getTimestamp() + "," + p.getValue());
+          }
+        }
+      } catch (Exception e) {
+        e.printStackTrace();
+      }
+    }
+  }
+
+  public static double getFSWParam(int nout, TimeSeries ts, double accuracy) throws IOException {
+    double epsilon = 1;
+    boolean directLess = false;
+    boolean directMore = false;
+    while (true) {
+      List<Point> reducedPoints = FSW.reducePoints(ts.data, epsilon);
+      if (reducedPoints.size() > nout) {
+        if (directMore) {
+          break;
+        }
+        if (!directLess) {
+          directLess = true;
+        }
+        epsilon *= 2;
+      } else {
+        if (directLess) {
+          break;
+        }
+        if (!directMore) {
+          directMore = true;
+        }
+        epsilon /= 2;
+      }
+    }
+    double left = 0;
+    double right = 0;
+    if (directLess) {
+      left = epsilon / 2;
+      right = epsilon;
+    }
+    if (directMore) {
+      left = epsilon;
+      right = epsilon * 2;
+    }
+    while (Math.abs(right - left) > accuracy) {
+      double mid = (left + right) / 2;
+      List<Point> reducedPoints = FSW.reducePoints(ts.data, mid);
+      if (reducedPoints.size() > nout) {
+        left = mid;
+      } else {
+        right = mid;
+      }
+    }
+    return (left + right) / 2;
+  }
+}