From 58661095bfe79a851c2f7c9f820187fe5d4fb3d0 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?David=20Proch=C3=A1zka?= <david@prochazka.dev>
Date: Wed, 24 Feb 2021 14:04:26 +0100
Subject: [PATCH] FIX: distance names
---
src/mhtree/MHTree.java | 2 +-
src/mhtree/Node.java | 58 ++++++++++------------------
src/mhtree/ObjectToNodeDistance.java | 4 +-
3 files changed, 24 insertions(+), 40 deletions(-)
diff --git a/src/mhtree/MHTree.java b/src/mhtree/MHTree.java
index f4c2170..e4a217f 100644
--- a/src/mhtree/MHTree.java
+++ b/src/mhtree/MHTree.java
@@ -87,7 +87,7 @@ public class MHTree extends Algorithm implements Serializable {
}
private boolean isPrunable(Node child, LocalAbstractObject queryObject, ApproxKNNQueryOperation operation, double coefficient) {
- return operation.getAnswerDistance() * coefficient < child.getDistanceToNearestHullObject(queryObject);
+ return operation.getAnswerDistance() * coefficient < child.getNearestDistance(queryObject);
}
public void insert(InsertOperation operation) throws BucketStorageException {
diff --git a/src/mhtree/Node.java b/src/mhtree/Node.java
index 731b688..a8065c3 100644
--- a/src/mhtree/Node.java
+++ b/src/mhtree/Node.java
@@ -6,8 +6,10 @@ import messif.buckets.BucketStorageException;
import messif.objects.LocalAbstractObject;
import java.io.Serializable;
-import java.util.*;
-import java.util.function.Function;
+import java.util.ArrayList;
+import java.util.Collection;
+import java.util.List;
+import java.util.Set;
import java.util.stream.Collectors;
public abstract class Node implements Serializable {
@@ -16,37 +18,36 @@ public abstract class Node implements Serializable {
* Serialization ID
*/
private static final long serialVersionUID = 420L;
- private final DistanceMeasure distanceMeasure;
+ private final ObjectToNodeDistance objectToNodeDistance;
+
protected final InsertType insertType;
protected HullOptimizedRepresentationV3 hull;
protected Node parent;
- Node(PrecomputedDistances distances, InsertType insertType, DistanceMeasure distanceMeasure) {
+ Node(PrecomputedDistances distances, InsertType insertType, ObjectToNodeDistance objectToNodeDistance) {
this.hull = new HullOptimizedRepresentationV3(distances);
this.hull.build();
this.insertType = insertType;
- this.distanceMeasure = distanceMeasure;
+ this.objectToNodeDistance = objectToNodeDistance;
}
- public static InternalNode createParent(Set<Node> nodes, PrecomputedDistances distances, InsertType insertType, DistanceMeasure distanceMeasure) {
+ public static InternalNode createParent(Set<Node> nodes, PrecomputedDistances distances, InsertType insertType, ObjectToNodeDistance objectToNodeDistance) {
List<LocalAbstractObject> objects = nodes.stream()
.map(Node::getObjects)
.flatMap(Collection::stream)
.collect(Collectors.toList());
- return new InternalNode(distances.getSubset(objects), insertType, distanceMeasure);
+ return new InternalNode(distances.getSubset(objects), insertType, objectToNodeDistance);
}
public double getDistance(LocalAbstractObject object) {
- switch (distanceMeasure) {
+ switch (objectToNodeDistance) {
case FURTHEST_HULL_OBJECT:
- return getDistanceToFurthestHullObject(object);
- case SUM_OF_DISTANCES_TO_HULL_OBJECTS:
- return getSumOfDistancesToHullObjects(object);
- case MEDOID:
- return getDistanceToMedoid(object);
+ return getFurthestDistance(object);
+ case AVERAGE_DISTANCE:
+ return getAverageDistance(object);
default:
- return getDistanceToNearestHullObject(object);
+ return getNearestDistance(object);
}
}
@@ -81,8 +82,6 @@ public abstract class Node implements Serializable {
public abstract boolean contains(LocalAbstractObject object);
- public abstract List<Integer> getLeafNodesObjectCounts();
-
public abstract int getHeight();
public abstract Set<Node> getNodesOnLevel(int level);
@@ -106,38 +105,23 @@ public abstract class Node implements Serializable {
rebuildHull(object);
}
- private static <T extends Collection<LocalAbstractObject>> double sumOfDistanceToObject(LocalAbstractObject object, T objects) {
- return objects.stream()
- .mapToDouble(object::getDistance)
- .sum();
- }
-
- private double getDistanceToNearestHullObject(LocalAbstractObject object) {
+ public double getNearestDistance(LocalAbstractObject object) {
return hull.getHull().stream()
.mapToDouble(object::getDistance)
.min()
.orElse(Double.MAX_VALUE);
}
- private double getDistanceToFurthestHullObject(LocalAbstractObject object) {
+ private double getFurthestDistance(LocalAbstractObject object) {
return hull.getHull().stream()
.mapToDouble(object::getDistance)
.max()
.orElse(Double.MIN_VALUE);
}
- private double getSumOfDistancesToHullObjects(LocalAbstractObject object) {
- return sumOfDistanceToObject(object, hull.getHull());
- }
-
- private double getDistanceToMedoid(LocalAbstractObject object) {
- Set<LocalAbstractObject> objects = getObjects();
-
- Map<LocalAbstractObject, Double> objectToObjectDistance = objects.stream()
- .collect(Collectors.toMap(Function.identity(), o -> sumOfDistanceToObject(o, objects)));
-
- LocalAbstractObject medoid = Collections.min(objectToObjectDistance.entrySet(), Map.Entry.comparingByValue()).getKey();
-
- return medoid.getDistance(object);
+ private double getAverageDistance(LocalAbstractObject object) {
+ return hull.getHull().stream()
+ .mapToDouble(object::getDistance)
+ .sum() / hull.getHull().size();
}
}
diff --git a/src/mhtree/ObjectToNodeDistance.java b/src/mhtree/ObjectToNodeDistance.java
index fc1d070..f9430f2 100644
--- a/src/mhtree/ObjectToNodeDistance.java
+++ b/src/mhtree/ObjectToNodeDistance.java
@@ -1,7 +1,7 @@
package mhtree;
-public enum DistanceMeasure {
+public enum ObjectToNodeDistance {
NEAREST_HULL_OBJECT,
FURTHEST_HULL_OBJECT,
- AVERAGE_DISTANCE
+ AVERAGE_DISTANCE,
}
--
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