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diff --git a/src/de/lmu/ifi/dbs/elki/math/statistics/distribution/estimator/LogGammaAlternateExpMADEstimator.java b/src/de/lmu/ifi/dbs/elki/math/statistics/distribution/estimator/LogGammaAlternateExpMADEstimator.java
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+++ b/src/de/lmu/ifi/dbs/elki/math/statistics/distribution/estimator/LogGammaAlternateExpMADEstimator.java
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+package de.lmu.ifi.dbs.elki.math.statistics.distribution.estimator;
+
+/*
+ This file is part of ELKI:
+ Environment for Developing KDD-Applications Supported by Index-Structures
+
+ Copyright (C) 2013
+ 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.math.statistics.distribution.LogGammaAlternateDistribution;
+import de.lmu.ifi.dbs.elki.utilities.optionhandling.AbstractParameterizer;
+
+/**
+ * Robust parameter estimation for the LogGamma distribution.
+ * 
+ * A modified algorithm for LogGamma distributions.
+ * 
+ * @author Erich Schubert
+ * 
+ * @apiviz.has LogGammaAlternateDistribution - - estimates
+ */
+public class LogGammaAlternateExpMADEstimator extends AbstractExpMADEstimator<LogGammaAlternateDistribution> {
+  /**
+   * Static estimator, more robust to outliers by using the median.
+   */
+  public static final LogGammaAlternateExpMADEstimator STATIC = new LogGammaAlternateExpMADEstimator();
+
+  /**
+   * Private constructor.
+   */
+  private LogGammaAlternateExpMADEstimator() {
+    // Do not instantiate - use static class
+  }
+
+  @Override
+  public LogGammaAlternateDistribution estimateFromExpMedianMAD(double median, double mad) {
+    if (median < Double.MIN_NORMAL) {
+      throw new ArithmeticException("Cannot estimate Gamma parameters on a distribution with zero median.");
+    }
+    if (mad < Double.MIN_NORMAL) {
+      throw new ArithmeticException("Cannot estimate Gamma parameters on a distribution with zero MAD.");
+    }
+
+    final double b = median / (mad * mad);
+    final double k = median * b;
+    if (!(k > 0.) || !(b > 0.)) {
+      throw new ArithmeticException("LogGammaAlternate estimation produced non-positive parameter values: k=" + k + " b=" + b + " median=" + median + " mad=" + mad);
+    }
+    return new LogGammaAlternateDistribution(k, Math.log(b), 0.);
+  }
+
+  @Override
+  public Class<? super LogGammaAlternateDistribution> getDistributionClass() {
+    return LogGammaAlternateDistribution.class;
+  }
+
+  /**
+   * Parameterization class.
+   * 
+   * @author Erich Schubert
+   * 
+   * @apiviz.exclude
+   */
+  public static class Parameterizer extends AbstractParameterizer {
+    @Override
+    protected LogGammaAlternateExpMADEstimator makeInstance() {
+      return STATIC;
+    }
+  }
+}