/**
* 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.filter;
import com.rapidminer.example.Attribute;
import com.rapidminer.example.ExampleSet;
import com.rapidminer.example.table.AttributeFactory;
import com.rapidminer.operator.OperatorDescription;
import com.rapidminer.operator.OperatorException;
import com.rapidminer.operator.annotation.ResourceConsumptionEstimator;
import com.rapidminer.operator.ports.metadata.AttributeMetaData;
import com.rapidminer.operator.ports.metadata.ExampleSetMetaData;
import com.rapidminer.tools.Ontology;
import com.rapidminer.tools.OperatorResourceConsumptionHandler;
/**
* Converts all nominal attributes to string attributes. Each nominal value is simply used as string
* value of the new attribute. If the value is missing, the new value will be missing.
*
* @author Ingo Mierswa
*/
public class Nominal2String extends AbstractFilteredDataProcessing {
public Nominal2String(OperatorDescription description) {
super(description);
}
@Override
public ExampleSet applyOnFiltered(ExampleSet exampleSet) throws OperatorException {
for (Attribute attribute : exampleSet.getAttributes()) {
if (attribute.isNominal()) {
Attribute newAttribute = AttributeFactory.changeValueType(attribute, Ontology.STRING);
exampleSet.getAttributes().replace(attribute, newAttribute);
}
}
return exampleSet;
}
@Override
public ExampleSetMetaData applyOnFilteredMetaData(ExampleSetMetaData emd) {
for (AttributeMetaData amd : emd.getAllAttributes()) {
if (amd.isNominal()) {
amd.setType(Ontology.STRING);
}
}
return emd;
}
@Override
protected int[] getFilterValueTypes() {
return new int[] { Ontology.NOMINAL };
}
@Override
public boolean writesIntoExistingData() {
return false;
}
@Override
public ResourceConsumptionEstimator getResourceConsumptionEstimator() {
return OperatorResourceConsumptionHandler
.getResourceConsumptionEstimator(getInputPort(), Nominal2String.class, null);
}
}