/**
* Licensed to the Apache Software Foundation (ASF) under one or more
* contributor license agreements. See the NOTICE file distributed with
* this work for additional information regarding copyright ownership.
* The ASF licenses this file to You under the Apache License, Version 2.0
* (the "License"); you may not use this file except in compliance with
* the License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package org.apache.mahout.classifier.naivebayes;
import java.util.Iterator;
import org.apache.mahout.classifier.AbstractVectorClassifier;
import org.apache.mahout.math.Vector;
import org.apache.mahout.math.Vector.Element;
/**
* Class implementing the Naive Bayes Classifier Algorithm
*
*/
public abstract class AbstractNaiveBayesClassifier extends AbstractVectorClassifier {
private final NaiveBayesModel model;
protected AbstractNaiveBayesClassifier(NaiveBayesModel model) {
this.model = model;
}
protected NaiveBayesModel getModel() {
return model;
}
public abstract double getScoreForLabelFeature(int label, int feature);
public double getScoreForLabelInstance(int label, Vector instance) {
double result = 0.0;
Iterator<Element> it = instance.iterateNonZero();
while (it.hasNext()) {
Element e = it.next();
result += getScoreForLabelFeature(label, e.index());
}
return result;
}
@Override
public int numCategories() {
return model.getNumLabels();
}
@Override
public Vector classify(Vector instance) {
Vector score = model.getLabelSum().like();
for (int i = 0; i < score.size(); i++) {
score.set(i, getScoreForLabelInstance(i, instance));
}
return score;
}
@Override
public double classifyScalar(Vector instance) {
throw new UnsupportedOperationException("Not supported in Naive Bayes");
}
}