Github user chiwanpark commented on a diff in the pull request:
https://github.com/apache/flink/pull/1220#discussion_r61398006
--- Diff:
flink-libraries/flink-ml/src/main/scala/org/apache/flink/ml/nn/QuadTree.scala
---
@@ -0,0 +1,344 @@
+/*
+ * 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.flink.ml.nn
+
+import org.apache.flink.ml.math.{Breeze, Vector}
+import Breeze._
+
+import
org.apache.flink.ml.metrics.distances.{SquaredEuclideanDistanceMetric,
+EuclideanDistanceMetric, DistanceMetric}
+
+import scala.collection.mutable.ListBuffer
+import scala.collection.mutable.PriorityQueue
+
+/**
+ * n-dimensional QuadTree data structure; partitions
+ * spatial data for faster queries (e.g. KNN query)
+ * The skeleton of the data structure was initially
+ * based off of the 2D Quadtree found here:
+ *
http://www.cs.trinity.edu/~mlewis/CSCI1321-F11/Code/src/util/Quadtree.scala
+ *
+ * Many additional methods were added to the class both for
+ * efficient KNN queries and generalizing to n-dim.
+ *
+ * @param minVec vector of the corner of the bounding box with smallest
coordinates
+ * @param maxVec vector of the corner of the bounding box with smallest
coordinates
+ * @param distMetric metric, must be Euclidean or squareEuclidean
+ * @param maxPerBox threshold for number of points in each box before
slitting a box
+ */
+class QuadTree(
+ minVec: Vector,
+ maxVec: Vector,
+ distMetric: DistanceMetric,
+ maxPerBox: Int) {
+
+ class Node(
+ center: Vector,
+ width: Vector,
+ var children: Seq[Node]) {
+
+ val nodeElements = new ListBuffer[Vector]
+
+ /** for testing purposes only; used in QuadTreeSuite.scala
+ *
+ * @return center and width of the box
+ */
+ def getCenterWidth(): (Vector, Vector) = {
+ (center, width)
+ }
+
+ def contains(queryPoint: Vector): Boolean = {
--- End diff --
Could you add a scaladoc for this method? All public methods should have a
scaladoc.
---
If your project is set up for it, you can reply to this email and have your
reply appear on GitHub as well. If your project does not have this feature
enabled and wishes so, or if the feature is enabled but not working, please
contact infrastructure at infrastruct...@apache.org or file a JIRA ticket
with INFRA.
---
