/**
* 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.weighting;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
import org.apache.commons.lang.ArrayUtils;
import com.rapidminer.example.Attribute;
import com.rapidminer.example.Attributes;
import com.rapidminer.example.Example;
import com.rapidminer.example.ExampleSet;
import com.rapidminer.example.Statistics;
import com.rapidminer.example.table.AttributeFactory;
import com.rapidminer.example.table.NominalMapping;
import com.rapidminer.operator.OperatorDescription;
import com.rapidminer.operator.OperatorException;
import com.rapidminer.operator.OperatorVersion;
import com.rapidminer.operator.annotation.ResourceConsumptionEstimator;
import com.rapidminer.operator.ports.metadata.SetRelation;
import com.rapidminer.parameter.ParameterType;
import com.rapidminer.parameter.ParameterTypeDouble;
import com.rapidminer.parameter.UndefinedParameterError;
import com.rapidminer.tools.Ontology;
import com.rapidminer.tools.OperatorResourceConsumptionHandler;
import com.rapidminer.tools.math.container.Range;
/**
* This operator distributes example weights so that all example weights of labels sum up equally.
*
* @author Sebastian Land
*/
public class EqualLabelWeighting extends AbstractExampleWeighting {
private static final String PARAMETER_TOTAL_WEIGHT = "total_weight";
/**
* Incompatible version, old version writes into the exampleset, if original output port is not
* connected.
*/
private static final OperatorVersion VERSION_MAY_WRITE_INTO_DATA = new OperatorVersion(7, 1, 1);
public EqualLabelWeighting(OperatorDescription description) {
super(description);
}
@Override
protected Range getWeightAttributeRange() {
try {
return new Range(0, getParameterAsDouble(PARAMETER_TOTAL_WEIGHT));
} catch (UndefinedParameterError e) {
return new Range(0, Double.POSITIVE_INFINITY);
}
}
@Override
protected SetRelation getWeightAttributeValueRelation() {
return SetRelation.SUPERSET;
}
@Override
public ExampleSet apply(ExampleSet exampleSet) throws OperatorException {
if (exampleSet.getAttributes().getWeight() == null) {
Attribute weight = AttributeFactory.createAttribute(Attributes.WEIGHT_NAME, Ontology.NUMERICAL);
exampleSet.getExampleTable().addAttribute(weight);
exampleSet.getAttributes().addRegular(weight);
exampleSet.getAttributes().setWeight(weight);
Attribute label = exampleSet.getAttributes().getLabel();
exampleSet.recalculateAttributeStatistics(label);
NominalMapping labelMapping = label.getMapping();
Map<String, Double> labelFrequencies = new HashMap<String, Double>();
for (String labelName : labelMapping.getValues()) {
labelFrequencies.put(labelName, exampleSet.getStatistics(label, Statistics.COUNT, labelName));
}
double numberOfLabels = labelFrequencies.size();
double perLabelWeight = getParameterAsDouble(PARAMETER_TOTAL_WEIGHT) / numberOfLabels;
for (Example example : exampleSet) {
double exampleWeight = perLabelWeight
/ labelFrequencies.get(labelMapping.mapIndex((int) example.getValue(label)));
example.setValue(weight, exampleWeight);
}
}
return exampleSet;
}
@Override
public List<ParameterType> getParameterTypes() {
List<ParameterType> types = super.getParameterTypes();
ParameterType type = new ParameterTypeDouble(PARAMETER_TOTAL_WEIGHT,
"The total weight distributed over all examples.", Double.NEGATIVE_INFINITY, Double.POSITIVE_INFINITY, 1);
type.setExpert(false);
types.add(type);
return types;
}
@Override
public boolean writesIntoExistingData() {
if (getCompatibilityLevel().isAbove(VERSION_MAY_WRITE_INTO_DATA)) {
return true;
} else {
// old version: true only if original output port is connected
return isOriginalOutputConnected();
}
}
@Override
public ResourceConsumptionEstimator getResourceConsumptionEstimator() {
return OperatorResourceConsumptionHandler.getResourceConsumptionEstimator(getInputPort(), EqualLabelWeighting.class,
null);
}
@Override
public OperatorVersion[] getIncompatibleVersionChanges() {
return (OperatorVersion[]) ArrayUtils.addAll(super.getIncompatibleVersionChanges(),
new OperatorVersion[] { VERSION_MAY_WRITE_INTO_DATA });
}
}