1 files changed, 76 insertions, 0 deletions
diff --git a/elki/src/test/java/de/lmu/ifi/dbs/elki/distance/distancefunction/correlation/PearsonCorrelationDistanceFunctionTest.java b/elki/src/test/java/de/lmu/ifi/dbs/elki/distance/distancefunction/correlation/PearsonCorrelationDistanceFunctionTest.java
new file mode 100644
index 00000000..bbe50452
--- /dev/null
+++ b/elki/src/test/java/de/lmu/ifi/dbs/elki/distance/distancefunction/correlation/PearsonCorrelationDistanceFunctionTest.java
@@ -0,0 +1,76 @@
+package de.lmu.ifi.dbs.elki.distance.distancefunction.correlation;
+
+/*
+ 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 static org.junit.Assert.assertEquals;
+
+import org.junit.Test;
+
+import de.lmu.ifi.dbs.elki.JUnit4Test;
+import de.lmu.ifi.dbs.elki.data.DoubleVector;
+
+/**
+ * Unit test for Pearson correlation distance.
+ * 
+ * @author Erich Schubert
+ * @since 0.7.0
+ */
+public class PearsonCorrelationDistanceFunctionTest implements JUnit4Test {
+  /**
+   * Some test series.
+   */
+  static final DoubleVector[] TESTS = { //
+  new DoubleVector(new double[] { 0., 1., 2., 3., 4., 5. }), //
+  new DoubleVector(new double[] { 0., .1, .2, .3, .4, .5 }), //
+  new DoubleVector(new double[] { -0., -1., -2., -3., -4., -5. }), //
+  new DoubleVector(new double[] { -5., -4., -3., -2., -1., 0. }), //
+  new DoubleVector(new double[] { 0., 0., 0., 0., 0., 0. }), //
+  new DoubleVector(new double[] { 0., 2., 4., 5., 3., 1. }), //
+  };
+
+  /** Dissimilarity for even-up,odd-down case */
+  static final double C1 = 0.7428571428571429;
+
+  /**
+   * The associated scores.
+   */
+  static final double[][] SCORES = { //
+  { 0., 0., 2., 0., 1., C1 },//
+  { 0., 0., 2., 0., 1., C1 },//
+  { 2., 2., 0., 2., 1., 2. - C1 },//
+  { 0., 0., 2., 0., 1., C1 },//
+  { 1., 1., 1., 1., 0., 1. },//
+  { C1, C1, 2. - C1, C1, 1., 0. },//
+  };
+
+  @Test
+  public void testPearson() {
+    PearsonCorrelationDistanceFunction f = PearsonCorrelationDistanceFunction.STATIC;
+    for(int i = 0; i < TESTS.length; i++) {
+      for(int j = 0; j < TESTS.length; j++) {
+        final double dist = f.distance(TESTS[i], TESTS[j]);
+        assertEquals("Distance does not agree: " + TESTS[i] + " <-> " + TESTS[j], SCORES[i][j], dist, 1e-15);
+      }
+    }
+  }
+}