/**
* 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.df;
import org.apache.mahout.classifier.df.builder.TreeBuilder;
import org.apache.mahout.classifier.df.data.Data;
import org.apache.mahout.classifier.df.node.Node;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import java.util.Arrays;
import java.util.Random;
/**
* Builds a tree using bagging
*/
public class Bagging {
private static final Logger log = LoggerFactory.getLogger(Bagging.class);
private final TreeBuilder treeBuilder;
private final Data data;
private final boolean[] sampled;
public Bagging(TreeBuilder treeBuilder, Data data) {
this.treeBuilder = treeBuilder;
this.data = data;
sampled = new boolean[data.size()];
}
/**
* Builds one tree
*/
public Node build(Random rng) {
log.debug("Bagging...");
Arrays.fill(sampled, false);
Data bag = data.bagging(rng, sampled);
log.debug("Building...");
return treeBuilder.build(rng, bag);
}
}