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diff --git a/src/de/lmu/ifi/dbs/elki/index/tree/spatial/rstarvariants/strategies/insert/LeastEnlargementInsertionStrategy.java b/src/de/lmu/ifi/dbs/elki/index/tree/spatial/rstarvariants/strategies/insert/LeastEnlargementInsertionStrategy.java
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+++ b/src/de/lmu/ifi/dbs/elki/index/tree/spatial/rstarvariants/strategies/insert/LeastEnlargementInsertionStrategy.java
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+package de.lmu.ifi.dbs.elki.index.tree.spatial.rstarvariants.strategies.insert;
+/*
+ This file is part of ELKI:
+ Environment for Developing KDD-Applications Supported by Index-Structures
+
+ Copyright (C) 2012
+ Ludwig-Maximilians-Universität München
+ Lehr- und Forschungseinheit für Datenbanksysteme
+ ELKI Development Team
+
+ This program is free software: you can redistribute it and/or modify
+ it under the terms of the GNU Affero General Public License as published by
+ the Free Software Foundation, either version 3 of the License, or
+ (at your option) any later version.
+
+ This program is distributed in the hope that it will be useful,
+ but WITHOUT ANY WARRANTY; without even the implied warranty of
+ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ GNU Affero General Public License for more details.
+
+ You should have received a copy of the GNU Affero General Public License
+ along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+import de.lmu.ifi.dbs.elki.data.spatial.SpatialComparable;
+import de.lmu.ifi.dbs.elki.data.spatial.SpatialUtil;
+import de.lmu.ifi.dbs.elki.utilities.datastructures.arraylike.ArrayAdapter;
+import de.lmu.ifi.dbs.elki.utilities.documentation.Reference;
+import de.lmu.ifi.dbs.elki.utilities.optionhandling.AbstractParameterizer;
+
+/**
+ * The default R-Tree insertion strategy: find rectangle with least volume
+ * enlargement.
+ * 
+ * <p>
+ * Antonin Guttman:<br/>
+ * R-Trees: A Dynamic Index Structure For Spatial Searching<br />
+ * in Proceedings of the 1984 ACM SIGMOD international conference on Management
+ * of data.
+ * </p>
+ * 
+ * @author Erich Schubert
+ */
+@Reference(authors = "Antonin Guttman", title = "R-Trees: A Dynamic Index Structure For Spatial Searching", booktitle = "Proceedings of the 1984 ACM SIGMOD international conference on Management of data", url = "http://dx.doi.org/10.1145/971697.602266")
+public class LeastEnlargementInsertionStrategy implements InsertionStrategy {
+  /**
+   * Static instance.
+   */
+  public static final LeastEnlargementInsertionStrategy STATIC = new LeastEnlargementInsertionStrategy();
+
+  /**
+   * Constructor.
+   */
+  public LeastEnlargementInsertionStrategy() {
+    super();
+  }
+
+  @Override
+  public <A> int choose(A options, ArrayAdapter<? extends SpatialComparable, A> getter, SpatialComparable obj, int height, int depth) {
+    final int size = getter.size(options);
+    assert (size > 0) : "Choose from empty set?";
+    double leastEnlargement = Double.POSITIVE_INFINITY;
+    int best = -1;
+    for(int i = 0; i < size; i++) {
+      SpatialComparable entry = getter.get(options, i);
+      double enlargement = SpatialUtil.enlargement(entry, obj);
+      if(enlargement < leastEnlargement) {
+        leastEnlargement = enlargement;
+        best = i;
+      }
+    }
+    assert (best > -1);
+    return best;
+  }
+
+  /**
+   * Parameterization class.
+   * 
+   * @author Erich Schubert
+   * 
+   * @apiviz.exclude
+   */
+  public static class Parameterizer extends AbstractParameterizer {
+    @Override
+    protected LeastEnlargementInsertionStrategy makeInstance() {
+      return LeastEnlargementInsertionStrategy.STATIC;
+    }
+  }
+}
+\ No newline at end of file