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diff --git a/src/de/lmu/ifi/dbs/elki/distance/distancefunction/JeffreyDivergenceDistanceFunction.java b/src/de/lmu/ifi/dbs/elki/distance/distancefunction/JeffreyDivergenceDistanceFunction.java
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+++ b/src/de/lmu/ifi/dbs/elki/distance/distancefunction/JeffreyDivergenceDistanceFunction.java
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+package de.lmu.ifi.dbs.elki.distance.distancefunction;
+
+/*
+ This file is part of ELKI:
+ Environment for Developing KDD-Applications Supported by Index-Structures
+
+ Copyright (C) 2011
+ 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.NumberVector;
+import de.lmu.ifi.dbs.elki.utilities.documentation.Reference;
+import de.lmu.ifi.dbs.elki.utilities.optionhandling.AbstractParameterizer;
+
+/**
+ * Provides the Jeffrey Divergence Distance for FeatureVectors.
+ * 
+ * @author Erich Schubert
+ */
+@Reference(authors="J. Puzicha,J.M. Buhmann, Y. Rubner, C. Tomasi", title="Empirical evaluation of dissimilarity measures for color and texture", booktitle="Proc. 7th IEEE International Conference on Computer Vision", url="http://dx.doi.org/10.1109/ICCV.1999.790412")
+public class JeffreyDivergenceDistanceFunction extends AbstractVectorDoubleDistanceFunction {
+  /**
+   * Static instance. Use this!
+   */
+  public static final JeffreyDivergenceDistanceFunction STATIC = new JeffreyDivergenceDistanceFunction();
+
+  /**
+   * Constructor for the Jeffrey divergence.
+   * 
+   * @deprecated Use static instance!
+   */
+  @Deprecated
+  public JeffreyDivergenceDistanceFunction() {
+  }
+
+  @Override
+  public double doubleDistance(NumberVector<?, ?> v1, NumberVector<?, ?> v2) {
+    final int dim1 = v1.getDimensionality();
+    if(dim1 != v2.getDimensionality()) {
+      throw new IllegalArgumentException("Different dimensionality of FeatureVectors" + "\n  first argument: " + v1.toString() + "\n  second argument: " + v2.toString() + "\n" + v1.getDimensionality() + "!=" + v2.getDimensionality());
+    }
+    double dist = 0;
+    for(int i = 1; i <= dim1; i++) {
+      final double xi = v1.doubleValue(i);
+      final double yi = v2.doubleValue(i);
+      final double mi = (xi + yi) / 2;
+      dist += xi * Math.log(xi / mi);
+      dist += yi * Math.log(yi / mi);
+    }
+    return dist;
+  }
+
+  @Override
+  public String toString() {
+    return "JeffreyDivergenceDistance";
+  }
+
+  @Override
+  public boolean equals(Object obj) {
+    if(obj == null) {
+      return false;
+    }
+    if(obj == this) {
+      return true;
+    }
+    if(this.getClass().equals(obj.getClass())) {
+      return true;
+    }
+    return super.equals(obj);
+  }
+
+  /**
+   * Parameterization class, using the static instance.
+   * 
+   * @author Erich Schubert
+   * 
+   * @apiviz.exclude
+   */
+  public static class Parameterizer extends AbstractParameterizer {
+    @Override
+    protected JeffreyDivergenceDistanceFunction makeInstance() {
+      return JeffreyDivergenceDistanceFunction.STATIC;
+    }
+  }
+}
+\ No newline at end of file