1 files changed, 74 insertions, 0 deletions
diff --git a/src/de/lmu/ifi/dbs/elki/distance/distancefunction/AbstractPrimitiveDistanceFunction.java b/src/de/lmu/ifi/dbs/elki/distance/distancefunction/AbstractPrimitiveDistanceFunction.java
new file mode 100644
index 00000000..2a13ca1a
--- /dev/null
+++ b/src/de/lmu/ifi/dbs/elki/distance/distancefunction/AbstractPrimitiveDistanceFunction.java
@@ -0,0 +1,74 @@
+package de.lmu.ifi.dbs.elki.distance.distancefunction;
+/*
+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 de.lmu.ifi.dbs.elki.database.query.distance.DistanceQuery;
+import de.lmu.ifi.dbs.elki.database.query.distance.PrimitiveDistanceQuery;
+import de.lmu.ifi.dbs.elki.database.relation.Relation;
+import de.lmu.ifi.dbs.elki.distance.distancevalue.Distance;
+
+/**
+ * AbstractDistanceFunction provides some methods valid for any extending class.
+ * 
+ * @author Arthur Zimek
+ * 
+ * @param <O> the type of objects to compute the distances in between
+ * @param <D> the type of Distance used
+ */
+public abstract class AbstractPrimitiveDistanceFunction<O, D extends Distance<D>> implements PrimitiveDistanceFunction<O, D> {
+  /**
+   * Provides an abstract DistanceFunction.
+   */
+  public AbstractPrimitiveDistanceFunction() {
+    // EMPTY
+  }
+
+  @Override
+  abstract public D distance(O o1, O o2);
+
+  @Override
+  abstract public D getDistanceFactory();
+
+  @Override
+  public boolean isSymmetric() {
+    // Assume symmetric by default!
+    return true;
+  }
+
+  @Override
+  public boolean isMetric() {
+    // Do NOT assume triangle equation by default!
+    return false;
+  }
+
+  /**
+   * Instantiate with a database to get the actual distance query.
+   * 
+   * @param relation Representation
+   * @return Actual distance query.
+   */
+  @Override
+  public <T extends O> DistanceQuery<T, D> instantiate(Relation<T> relation) {
+    return new PrimitiveDistanceQuery<T, D>(relation, this);
+  }
+}
+\ No newline at end of file