/**
* Copyright (C) 2001-2017 by RapidMiner and the contributors
*
* Complete list of developers available at our web site:
*
* http://rapidminer.com
*
* 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/.
*/
package com.rapidminer.operator.preprocessing.normalization;
import com.rapidminer.example.Attribute;
import com.rapidminer.example.ExampleSet;
import com.rapidminer.example.Statistics;
import com.rapidminer.operator.Operator;
import com.rapidminer.operator.UserError;
import com.rapidminer.operator.ports.InputPort;
import com.rapidminer.operator.ports.metadata.AttributeMetaData;
import com.rapidminer.operator.ports.metadata.ExampleSetMetaData;
import com.rapidminer.operator.ports.metadata.MDReal;
import com.rapidminer.operator.ports.metadata.SetRelation;
import com.rapidminer.parameter.ParameterHandler;
import com.rapidminer.parameter.UndefinedParameterError;
import com.rapidminer.tools.container.Tupel;
import com.rapidminer.tools.math.container.Range;
import java.util.Collection;
import java.util.Collections;
import java.util.HashMap;
/**
* The normalization method for the Z-Transformation
*
* @author Sebastian Land
*/
public class ZTransformationNormalizationMethod extends AbstractNormalizationMethod {
@Override
public Collection<AttributeMetaData> modifyAttributeMetaData(ExampleSetMetaData emd, AttributeMetaData amd,
InputPort exampleSetInputPort, ParameterHandler parameterHandler) throws UndefinedParameterError {
amd.setMean(new MDReal((double) 0));
amd.setValueRange(new Range(Double.NEGATIVE_INFINITY, Double.POSITIVE_INFINITY), SetRelation.SUBSET);
return Collections.singleton(amd);
}
@Override
public AbstractNormalizationModel getNormalizationModel(ExampleSet exampleSet, Operator operator) throws UserError {
// Z-Transformation
exampleSet.recalculateAllAttributeStatistics();
HashMap<String, Tupel<Double, Double>> attributeMeanVarianceMap = new HashMap<String, Tupel<Double, Double>>();
for (Attribute attribute : exampleSet.getAttributes()) {
if (attribute.isNumerical()) {
attributeMeanVarianceMap.put(
attribute.getName(),
new Tupel<Double, Double>(exampleSet.getStatistics(attribute, Statistics.AVERAGE), exampleSet
.getStatistics(attribute, Statistics.VARIANCE)));
}
}
ZTransformationModel model = new ZTransformationModel(exampleSet, attributeMeanVarianceMap);
return model;
}
@Override
public String getName() {
return "Z-transformation";
}
}