/**
* 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.transformation.aggregation;
import com.rapidminer.example.Attribute;
import com.rapidminer.tools.Ontology;
/**
* This class implements the Variance Aggregation function. This will calculate the variance of a
* source attribute for each group.
*
* @author Sebastian Land
*/
public class VarianceAggregationFunction extends NumericalAggregationFunction {
public static final String FUNCTION_VARIANCE = "variance";
public VarianceAggregationFunction(Attribute sourceAttribute, boolean ignoreMissings, boolean countOnlyDisctinct) {
super(sourceAttribute, ignoreMissings, countOnlyDisctinct, FUNCTION_VARIANCE, FUNCTION_SEPARATOR_OPEN,
FUNCTION_SEPARATOR_CLOSE);
}
public VarianceAggregationFunction(Attribute sourceAttribute, boolean ignoreMissings, boolean countOnlyDisctinct,
String functionName, String separatorOpen, String separatorClose) {
super(sourceAttribute, ignoreMissings, countOnlyDisctinct, functionName, separatorOpen, separatorClose);
}
@Override
public Aggregator createAggregator() {
return new VarianceAggregator(this);
}
@Override
protected int getTargetValueType(int sourceValueType) {
return Ontology.REAL;
}
@Override
public boolean isCompatible() {
return getSourceAttribute().isNumerical();
}
}