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Diffstat (limited to 'src/de/lmu/ifi/dbs/elki/datasource/filter/normalization/columnwise/AttributeWiseErfNormalization.java')
-rw-r--r-- | src/de/lmu/ifi/dbs/elki/datasource/filter/normalization/columnwise/AttributeWiseErfNormalization.java | 76 |
1 files changed, 76 insertions, 0 deletions
diff --git a/src/de/lmu/ifi/dbs/elki/datasource/filter/normalization/columnwise/AttributeWiseErfNormalization.java b/src/de/lmu/ifi/dbs/elki/datasource/filter/normalization/columnwise/AttributeWiseErfNormalization.java new file mode 100644 index 00000000..e4af3a92 --- /dev/null +++ b/src/de/lmu/ifi/dbs/elki/datasource/filter/normalization/columnwise/AttributeWiseErfNormalization.java @@ -0,0 +1,76 @@ +package de.lmu.ifi.dbs.elki.datasource.filter.normalization.columnwise; + +/* + This file is part of ELKI: + Environment for Developing KDD-Applications Supported by Index-Structures + + Copyright (C) 2014 + 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.data.NumberVector; +import de.lmu.ifi.dbs.elki.data.type.SimpleTypeInformation; +import de.lmu.ifi.dbs.elki.data.type.TypeUtil; +import de.lmu.ifi.dbs.elki.datasource.filter.normalization.AbstractNormalization; +import de.lmu.ifi.dbs.elki.logging.Logging; +import de.lmu.ifi.dbs.elki.math.statistics.distribution.NormalDistribution; +import de.lmu.ifi.dbs.elki.utilities.Alias; + +/** + * Attribute-wise Normalization using the error function. This mostly makes + * sense when you have data that has been mean-variance normalized before. + * + * @author Erich Schubert + * + * @param <V> Object type + * + * @apiviz.uses NumberVector + */ +@Alias({ "de.lmu.ifi.dbs.elki.datasource.filter.normalization.AttributeWiseErfNormalization"}) +public class AttributeWiseErfNormalization<V extends NumberVector> extends AbstractNormalization<V> { + /** + * Class logger. + */ + private static final Logging LOG = Logging.getLogger(AttributeWiseErfNormalization.class); + + /** + * Constructor. + */ + public AttributeWiseErfNormalization() { + super(); + } + + @Override + protected V filterSingleObject(V obj) { + double[] val = new double[obj.getDimensionality()]; + for(int i = 0; i < val.length; i++) { + val[i] = NormalDistribution.erf(obj.doubleValue(i)); + } + return factory.newNumberVector(val); + } + + @Override + protected Logging getLogger() { + return LOG; + } + + @Override + protected SimpleTypeInformation<? super V> getInputTypeRestriction() { + return TypeUtil.NUMBER_VECTOR_FIELD; + } +} |