1 files changed, 107 insertions, 0 deletions
diff --git a/src/de/lmu/ifi/dbs/elki/math/linearalgebra/pca/CompositeEigenPairFilter.java b/src/de/lmu/ifi/dbs/elki/math/linearalgebra/pca/CompositeEigenPairFilter.java
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+package de.lmu.ifi.dbs.elki.math.linearalgebra.pca;
+/*
+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.List;
+
+import de.lmu.ifi.dbs.elki.math.linearalgebra.SortedEigenPairs;
+import de.lmu.ifi.dbs.elki.utilities.optionhandling.AbstractParameterizer;
+import de.lmu.ifi.dbs.elki.utilities.optionhandling.OptionID;
+import de.lmu.ifi.dbs.elki.utilities.optionhandling.parameterization.Parameterization;
+import de.lmu.ifi.dbs.elki.utilities.optionhandling.parameters.ObjectListParameter;
+
+/**
+ * The <code>CompositeEigenPairFilter</code> can be used to build a chain of
+ * eigenpair filters.
+ * 
+ * @author Elke Achtert
+ */
+// todo parameter comments
+public class CompositeEigenPairFilter implements EigenPairFilter {
+  /**
+   * The list of filters to use.
+   */
+  public static final OptionID EIGENPAIR_FILTER_COMPOSITE_LIST = OptionID.getOrCreateOptionID("pca.filter.composite.list", "A comma separated list of the class names of the filters to be used. " + "The specified filters will be applied sequentially in the given order.");
+
+  /**
+   * The filters to be applied.
+   */
+  private List<EigenPairFilter> filters;
+
+  /**
+   * Constructor.
+   * 
+   * @param filters Filters to use.
+   */
+  public CompositeEigenPairFilter(List<EigenPairFilter> filters) {
+    super();
+    this.filters = filters;
+  }
+
+  /**
+   * Filters the specified eigenpairs into strong and weak eigenpairs, where
+   * strong eigenpairs having high variances and weak eigenpairs having small
+   * variances.
+   * 
+   * @param eigenPairs the eigenPairs (i.e. the eigenvectors and
+   * @return the filtered eigenpairs
+   */
+  @Override
+  public FilteredEigenPairs filter(SortedEigenPairs eigenPairs) {
+    FilteredEigenPairs result = null;
+    for(EigenPairFilter f : filters) {
+      result = f.filter(eigenPairs);
+      eigenPairs = new SortedEigenPairs(result.getStrongEigenPairs());
+    }
+    return result;
+  }
+
+  /**
+   * Parameterization class.
+   * 
+   * @author Erich Schubert
+   * 
+   * @apiviz.exclude
+   */
+  public static class Parameterizer extends AbstractParameterizer {
+    /**
+     * The filters to be applied.
+     */
+    private List<EigenPairFilter> filters = null;
+
+    @Override
+    protected void makeOptions(Parameterization config) {
+      super.makeOptions(config);
+      ObjectListParameter<EigenPairFilter> filtersP = new ObjectListParameter<EigenPairFilter>(EIGENPAIR_FILTER_COMPOSITE_LIST, EigenPairFilter.class);
+
+      if(config.grab(filtersP)) {
+        filters = filtersP.instantiateClasses(config);
+      }
+    }
+
+    @Override
+    protected CompositeEigenPairFilter makeInstance() {
+      return new CompositeEigenPairFilter(filters);
+    }
+  }
+}
+\ No newline at end of file