FloatAverageAggregator.java

/*
 * 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.openflamingo.mapreduce.aggregator;


import org.apache.hadoop.io.FloatWritable;

/**
 * Aggregator for averaging float values.
 */
public class FloatAverageAggregator implements Aggregator<FloatWritable> {
	/**
	 * Aggregated sum
	 */
	private float sum = 0;
	/**
	 * Number of aggregated numbers
	 */
	private long count = 0;

	/**
	 * Aggregate a primitive float.
	 *
	 * @param value Float value to aggregate.
	 */
	public void aggregate(float value) {
		sum += value;
		count++;
	}

	@Override
	public void aggregate(FloatWritable value) {
		sum += value.get();
		count++;
	}

	/**
	 * Reset the aggregated value.
	 */
	public void resetAggregatedValue() {
		sum = 0.0f;
		count = 0;
	}

	/**
	 * This method should not be used, use resetAggregatedValue()
	 *
	 * @param value Float value to aggregate.
	 */
	@Override
	public void setAggregatedValue(FloatWritable value) {
	}

	@Override
	public FloatWritable getAggregatedValue() {
		return new FloatWritable(count > 0 ? sum / count : 0.0f);
	}

	@Override
	public FloatWritable createAggregatedValue() {
		return new FloatWritable();
	}

}