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Diffstat (limited to 'src/de/lmu/ifi/dbs/elki/datasource/filter/normalization/AttributeWiseErfNormalization.java')
-rw-r--r-- | src/de/lmu/ifi/dbs/elki/datasource/filter/normalization/AttributeWiseErfNormalization.java | 67 |
1 files changed, 67 insertions, 0 deletions
diff --git a/src/de/lmu/ifi/dbs/elki/datasource/filter/normalization/AttributeWiseErfNormalization.java b/src/de/lmu/ifi/dbs/elki/datasource/filter/normalization/AttributeWiseErfNormalization.java new file mode 100644 index 00000000..c0f2a955 --- /dev/null +++ b/src/de/lmu/ifi/dbs/elki/datasource/filter/normalization/AttributeWiseErfNormalization.java @@ -0,0 +1,67 @@ +package de.lmu.ifi.dbs.elki.datasource.filter.normalization; + +/* + This file is part of ELKI: + Environment for Developing KDD-Applications Supported by Index-Structures + + Copyright (C) 2012 + 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.math.statistics.distribution.NormalDistribution; + +/** + * 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 <O> Object type + * + * @apiviz.uses NumberVector + */ +public class AttributeWiseErfNormalization<O extends NumberVector<O, ?>> extends AbstractNormalization<O> { + /** + * Constructor. + */ + public AttributeWiseErfNormalization() { + super(); + } + + @Override + public O restore(O featureVector) throws NonNumericFeaturesException { + throw new UnsupportedOperationException("Not implemented yet."); + } + + @Override + protected O filterSingleObject(O obj) { + double[] val = new double[obj.getDimensionality()]; + for(int i = 0; i < val.length; i++) { + val[i] = NormalDistribution.erf(obj.doubleValue(i + 1)); + } + return obj.newNumberVector(val); + } + + @Override + protected SimpleTypeInformation<? super O> getInputTypeRestriction() { + return TypeUtil.NUMBER_VECTOR_FIELD; + } +} |