1 files changed, 17 insertions, 15 deletions
diff --git a/src/de/lmu/ifi/dbs/elki/math/dimensionsimilarity/SlopeDimensionSimilarity.java b/src/de/lmu/ifi/dbs/elki/math/dimensionsimilarity/SlopeDimensionSimilarity.java
index 1eb62189..b48a2410 100644
--- a/src/de/lmu/ifi/dbs/elki/math/dimensionsimilarity/SlopeDimensionSimilarity.java
+++ b/src/de/lmu/ifi/dbs/elki/math/dimensionsimilarity/SlopeDimensionSimilarity.java
@@ -4,7 +4,7 @@ package de.lmu.ifi.dbs.elki.math.dimensionsimilarity;
  This file is part of ELKI:
  Environment for Developing KDD-Applications Supported by Index-Structures
 
- Copyright (C) 2012
+ Copyright (C) 2014
  Ludwig-Maximilians-Universität München
  Lehr- und Forschungseinheit für Datenbanksysteme
  ELKI Development Team
@@ -28,10 +28,9 @@ import de.lmu.ifi.dbs.elki.database.Database;
 import de.lmu.ifi.dbs.elki.database.ids.DBIDIter;
 import de.lmu.ifi.dbs.elki.database.ids.DBIDs;
 import de.lmu.ifi.dbs.elki.database.relation.Relation;
-import de.lmu.ifi.dbs.elki.utilities.DatabaseUtil;
+import de.lmu.ifi.dbs.elki.database.relation.RelationUtil;
 import de.lmu.ifi.dbs.elki.utilities.documentation.Reference;
 import de.lmu.ifi.dbs.elki.utilities.optionhandling.AbstractParameterizer;
-import de.lmu.ifi.dbs.elki.utilities.pairs.Pair;
 
 /**
  * Arrange dimensions based on the entropy of the slope spectrum.
@@ -43,12 +42,17 @@ import de.lmu.ifi.dbs.elki.utilities.pairs.Pair;
  * Proceedings of the 2013 ACM International Conference on Management of Data
  * (SIGMOD), New York City, NY, 2013.
  * </p>
- *
+ * 
+ * TODO: shouldn't this be normalized by the single-dimension entropies or so?
+ * 
  * @author Erich Schubert
  * @author Robert Rödler
  */
-@Reference(authors = "Elke Achtert, Hans-Peter Kriegel, Erich Schubert, Arthur Zimek", title = "Interactive Data Mining with 3D-Parallel-Coordinate-Trees", booktitle = "Proc. of the 2013 ACM International Conference on Management of Data (SIGMOD)", url = "http://dx.doi.org/10.1145/2463676.2463696")
-public class SlopeDimensionSimilarity implements DimensionSimilarity<NumberVector<?>> {
+@Reference(authors = "Elke Achtert, Hans-Peter Kriegel, Erich Schubert, Arthur Zimek", //
+title = "Interactive Data Mining with 3D-Parallel-Coordinate-Trees", //
+booktitle = "Proc. of the 2013 ACM International Conference on Management of Data (SIGMOD)", //
+url = "http://dx.doi.org/10.1145/2463676.2463696")
+public class SlopeDimensionSimilarity implements DimensionSimilarity<NumberVector> {
   /**
    * Static instance.
    */
@@ -77,21 +81,19 @@ public class SlopeDimensionSimilarity implements DimensionSimilarity<NumberVecto
   }
 
   @Override
-  public void computeDimensionSimilarites(Database database, Relation<? extends NumberVector<?>> relation, DBIDs subset, DimensionSimilarityMatrix matrix) {
+  public void computeDimensionSimilarites(Database database, Relation<? extends NumberVector> relation, DBIDs subset, DimensionSimilarityMatrix matrix) {
     final int dim = matrix.size();
     final int size = subset.size();
 
     // FIXME: Get/keep these statistics in the relation, or compute for the
     // sample only.
-    double[] off = new double[dim], scale = new double[dim];
+    double[] off, scale;
     {
-      Pair<? extends NumberVector<?>, ? extends NumberVector<?>> mm = DatabaseUtil.computeMinMax(relation);
-      NumberVector<?> min = mm.first;
-      NumberVector<?> max = mm.second;
+      double[][] mm = RelationUtil.computeMinMax(relation);
+      off = mm[0]; scale = mm[1];
       for (int d = 0; d < dim; d++) {
-        off[d] = min.doubleValue(matrix.dim(d));
-        final double m = max.doubleValue(matrix.dim(d));
-        scale[d] = (m > off[d]) ? 1. / (m - off[d]) : 1;
+        scale[d] -= off[d];
+        scale[d] = (scale[d] > 0.) ? 1. / scale[d] : 1.;
       }
     }
 
@@ -102,7 +104,7 @@ public class SlopeDimensionSimilarity implements DimensionSimilarity<NumberVecto
     // Scratch buffer
     double[] vec = new double[dim];
     for (DBIDIter id = subset.iter(); id.valid(); id.advance()) {
-      final NumberVector<?> obj = relation.get(id);
+      final NumberVector obj = relation.get(id);
       // Map values to 0..1
       for (int d = 0; d < dim; d++) {
         vec[d] = (obj.doubleValue(matrix.dim(d)) - off[d]) * scale[d];