/**
* 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.learner.rules;
import com.rapidminer.example.Attribute;
import com.rapidminer.example.Example;
import com.rapidminer.example.ExampleSet;
/**
* Calculates the accuracy benefit.
*
* @author Sebastian Land, Ingo Mierswa
*/
public class AccuracyCriterion extends AbstractCriterion {
@Override
public double[] getBenefit(ExampleSet coveredSet, ExampleSet uncoveredSet, String labelName) {
double labelSum = 0;
double totalSum = 0;
Attribute weightAttribute = coveredSet.getAttributes().getWeight();
Attribute labelAttribute = coveredSet.getAttributes().getLabel();
double labelValue = labelAttribute.getMapping().getIndex(labelName);
for (Example e : coveredSet) {
double weight = 1.0d;
if (weightAttribute != null) {
weight = e.getValue(weightAttribute);
}
totalSum += weight;
if (e.getValue(labelAttribute) == labelValue) {
labelSum += weight;
}
}
return new double[] { labelSum / totalSum, totalSum };
}
@Override
public double[] getOnlineBenefit(Example example, int labelIndex) {
double accuracy = labelWeights[labelIndex] / weight;
double reverseAccuracy = (totalLabelWeights[labelIndex] - labelWeights[labelIndex]) / (totalWeight - weight);
return new double[] { accuracy, weight, reverseAccuracy, totalWeight - weight };
}
}