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diff --git a/elki/src/main/java/de/lmu/ifi/dbs/elki/utilities/scaling/outlier/TopKOutlierScaling.java b/elki/src/main/java/de/lmu/ifi/dbs/elki/utilities/scaling/outlier/TopKOutlierScaling.java
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+++ b/elki/src/main/java/de/lmu/ifi/dbs/elki/utilities/scaling/outlier/TopKOutlierScaling.java
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+package de.lmu.ifi.dbs.elki.utilities.scaling.outlier;
+
+/*
+ This file is part of ELKI:
+ Environment for Developing KDD-Applications Supported by Index-Structures
+
+ Copyright (C) 2015
+ 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.database.ids.DBIDIter;
+import de.lmu.ifi.dbs.elki.logging.LoggingUtil;
+import de.lmu.ifi.dbs.elki.result.outlier.OutlierResult;
+import de.lmu.ifi.dbs.elki.utilities.datastructures.QuickSelect;
+import de.lmu.ifi.dbs.elki.utilities.datastructures.arraylike.ArrayLikeUtil;
+import de.lmu.ifi.dbs.elki.utilities.datastructures.arraylike.NumberArrayAdapter;
+import de.lmu.ifi.dbs.elki.utilities.optionhandling.AbstractParameterizer;
+import de.lmu.ifi.dbs.elki.utilities.optionhandling.OptionID;
+import de.lmu.ifi.dbs.elki.utilities.optionhandling.constraints.CommonConstraints;
+import de.lmu.ifi.dbs.elki.utilities.optionhandling.parameterization.Parameterization;
+import de.lmu.ifi.dbs.elki.utilities.optionhandling.parameters.Flag;
+import de.lmu.ifi.dbs.elki.utilities.optionhandling.parameters.IntParameter;
+
+/**
+ * Outlier scaling function that only keeps the top k outliers.
+ * 
+ * @author Erich Schubert
+ */
+public class TopKOutlierScaling implements OutlierScalingFunction {
+  /**
+   * Parameter to specify the number of outliers to keep
+   * <p>
+   * Key: {@code -topk.k}
+   * </p>
+   */
+  public static final OptionID K_ID = new OptionID("topk.k", "Number of outliers to keep.");
+
+  /**
+   * Parameter to specify the lambda value
+   * <p>
+   * Key: {@code -topk.binary}
+   * </p>
+   */
+  public static final OptionID BINARY_ID = new OptionID("topk.binary", "Make the top k a binary scaling.");
+
+  /**
+   * Number of outliers to keep.
+   */
+  private int k = -1;
+
+  /**
+   * Do a binary decision
+   */
+  private boolean binary = false;
+
+  /**
+   * The value we cut off at.
+   */
+  private double cutoff;
+
+  /**
+   * The "ground" value
+   */
+  private double ground;
+
+  /**
+   * The maximum value
+   */
+  private double max;
+
+  /**
+   * Constructor.
+   * 
+   * @param k
+   * @param binary
+   */
+  public TopKOutlierScaling(int k, boolean binary) {
+    super();
+    this.k = k;
+    this.binary = binary;
+  }
+
+  @Override
+  public void prepare(OutlierResult or) {
+    if(k <= 0) {
+      LoggingUtil.warning("No k configured for Top-k outlier scaling!");
+    }
+    DBIDIter order = or.getOrdering().order(or.getOrdering().getDBIDs()).iter();
+    for(int i = 0; i < k && order.valid(); i++, order.advance()) {
+      cutoff = or.getScores().doubleValue(order);
+    }
+    max = or.getOutlierMeta().getActualMaximum();
+    ground = or.getOutlierMeta().getTheoreticalBaseline();
+    if(Double.isInfinite(ground) || Double.isNaN(ground)) {
+      ground = or.getOutlierMeta().getTheoreticalMinimum();
+    }
+    if(Double.isInfinite(ground) || Double.isNaN(ground)) {
+      ground = or.getOutlierMeta().getActualMinimum();
+    }
+    if(Double.isInfinite(ground) || Double.isNaN(ground)) {
+      ground = Math.min(0.0, cutoff);
+    }
+  }
+
+  @Override
+  public <A> void prepare(A array, NumberArrayAdapter<?, A> adapter) {
+    if(k <= 0) {
+      LoggingUtil.warning("No k configured for Top-k outlier scaling!");
+    }
+    double[] scores = ArrayLikeUtil.toPrimitiveDoubleArray(array, adapter);
+    QuickSelect.quickSelect(scores, k);
+    cutoff = scores[k - 1];
+    max = Double.NEGATIVE_INFINITY;
+    for(double v : scores) {
+      max = Math.max(max, v);
+    }
+    ground = Math.min(0.0, cutoff);
+  }
+
+  @Override
+  public double getMax() {
+    if(binary) {
+      return 1.0;
+    }
+    return max;
+  }
+
+  @Override
+  public double getMin() {
+    if(binary) {
+      return 0.0;
+    }
+    return ground;
+  }
+
+  @Override
+  public double getScaled(double value) {
+    if(binary) {
+      if(value >= cutoff) {
+        return 1;
+      }
+      else {
+        return 0;
+      }
+    }
+    else {
+      if(value >= cutoff) {
+        return (value - ground) / (max - ground);
+      }
+      else {
+        return 0.0;
+      }
+    }
+  }
+
+  /**
+   * Parameterization class.
+   * 
+   * @author Erich Schubert
+   * 
+   * @apiviz.exclude
+   */
+  public static class Parameterizer extends AbstractParameterizer {
+    protected int k = 0;
+
+    protected boolean binary = false;
+
+    @Override
+    protected void makeOptions(Parameterization config) {
+      super.makeOptions(config);
+      IntParameter kP = new IntParameter(K_ID);
+      kP.addConstraint(CommonConstraints.GREATER_THAN_ONE_INT);
+      if(config.grab(kP)) {
+        k = kP.intValue();
+      }
+
+      Flag binaryF = new Flag(BINARY_ID);
+      if(config.grab(binaryF)) {
+        binary = binaryF.isTrue();
+      }
+    }
+
+    @Override
+    protected TopKOutlierScaling makeInstance() {
+      return new TopKOutlierScaling(k, binary);
+    }
+  }
+}