1 files changed, 47 insertions, 0 deletions
diff --git a/test/de/lmu/ifi/dbs/elki/algorithm/clustering/TestEMResults.java b/test/de/lmu/ifi/dbs/elki/algorithm/clustering/TestEMResults.java
new file mode 100644
index 00000000..e3e4c984
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+++ b/test/de/lmu/ifi/dbs/elki/algorithm/clustering/TestEMResults.java
@@ -0,0 +1,47 @@
+package de.lmu.ifi.dbs.elki.algorithm.clustering;
+
+import org.junit.Test;
+
+import de.lmu.ifi.dbs.elki.JUnit4Test;
+import de.lmu.ifi.dbs.elki.algorithm.AbstractSimpleAlgorithmTest;
+import de.lmu.ifi.dbs.elki.data.Clustering;
+import de.lmu.ifi.dbs.elki.data.DoubleVector;
+import de.lmu.ifi.dbs.elki.data.model.EMModel;
+import de.lmu.ifi.dbs.elki.database.Database;
+import de.lmu.ifi.dbs.elki.utilities.ClassGenericsUtil;
+import de.lmu.ifi.dbs.elki.utilities.optionhandling.ParameterException;
+import de.lmu.ifi.dbs.elki.utilities.optionhandling.parameterization.ListParameterization;
+
+/**
+ * Performs a full EM run, and compares the result with a clustering derived
+ * from the data set labels. This test ensures that EM's performance doesn't
+ * unexpectedly drop on this data set (and also ensures that the algorithms
+ * work, as a side effect).
+ * 
+ * @author Katharina Rausch
+ * @author Erich Schubert
+ */
+public class TestEMResults extends AbstractSimpleAlgorithmTest implements JUnit4Test {
+  /**
+   * Run EM with fixed parameters and compare the result to a golden
+   * standard.
+   * 
+   * @throws ParameterException
+   */
+  @Test
+  public void testEMResults() {
+    Database db = makeSimpleDatabase(UNITTEST + "hierarchical-2d.ascii", 710);
+
+    // Setup algorithm
+    ListParameterization params = new ListParameterization();
+    params.addParameter(EM.SEED_ID, 1);
+    params.addParameter(EM.K_ID, 5);
+    EM<DoubleVector> em = ClassGenericsUtil.parameterizeOrAbort(EM.class, params);
+    testParameterizationOk(params);
+
+    // run EM on database
+    Clustering<EMModel<DoubleVector>> result = em.run(db);
+    testFMeasure(db, result, 0.961587);
+    testClusterSizes(result, new int[] { 5, 91, 98, 200, 316 });
+  }
+}
+\ No newline at end of file