1 files changed, 90 insertions, 0 deletions
diff --git a/src/de/lmu/ifi/dbs/elki/evaluation/paircounting/generator/PairGeneratorNoise.java b/src/de/lmu/ifi/dbs/elki/evaluation/paircounting/generator/PairGeneratorNoise.java
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+++ b/src/de/lmu/ifi/dbs/elki/evaluation/paircounting/generator/PairGeneratorNoise.java
@@ -0,0 +1,90 @@
+package de.lmu.ifi.dbs.elki.evaluation.paircounting.generator;
+/*
+This file is part of ELKI:
+Environment for Developing KDD-Applications Supported by Index-Structures
+
+Copyright (C) 2011
+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 java.util.Arrays;
+
+import de.lmu.ifi.dbs.elki.data.Cluster;
+import de.lmu.ifi.dbs.elki.database.ids.DBID;
+import de.lmu.ifi.dbs.elki.database.ids.DBIDs;
+import de.lmu.ifi.dbs.elki.utilities.pairs.IntIntPair;
+
+/**
+ * Generator for noise points.
+ * 
+ * This generator will generate pairs (a,a) for all elements a in the given
+ * list.
+ * 
+ * @author Erich Schubert
+ */
+public class PairGeneratorNoise extends PairSortedGenerator {
+  /**
+   * Ids to use
+   */
+  private int[] ids;
+
+  /**
+   * Current position.
+   */
+  private int pos;
+
+  /**
+   * Crate new generator for a base cluster object.
+   * 
+   * @param cluster object
+   */
+  public PairGeneratorNoise(Cluster<?> cluster) {
+    // build int array for the cluster
+    // TODO: copy less.
+    DBIDs dbids = cluster.getIDs();
+    ids = new int[dbids.size()];
+    int j = 0;
+    for (DBID id : dbids) {
+      ids[j] = id.getIntegerID();
+      j++;
+    }
+    Arrays.sort(ids);
+
+    pos = 0;
+    if(ids.length > 0) {
+      setCurrent(new IntIntPair(ids[pos], ids[pos]));
+    }
+  }
+
+  /**
+   * Advance iterator and return new pair.
+   */
+  @Override
+  protected IntIntPair advance() {
+    if(current() == null) {
+      return null;
+    }
+    pos++;
+    if(pos >= ids.length) {
+      return null;
+    }
+    else {
+      return new IntIntPair(ids[pos], ids[pos]);
+    }
+  }
+}
+\ No newline at end of file