org.conqat.lib.commons.math.MeanAggregator Maven / Gradle / Ivy

Show more of this group Show more artifacts with this name
Show all versions of teamscale-lib-commons Show documentation

Provides common utility functions

The newest version!

/*
 * Copyright (c) CQSE GmbH
 *
 * Licensed 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.conqat.lib.commons.math;

import java.util.Collection;

/**
 * Average aggregator.
 * 
 * @author deissenb
 */
public class MeanAggregator implements IAggregator {

	/**
	 * Aggregates by finding the average value
	 * 
	 * @return {@link Double#NaN} for empty input collection
	 */
	@Override
	public double aggregate(Collection values) {
		if (values.isEmpty()) {
			return Double.NaN;
		}
		return MathUtils.sum(values) / values.size();
	}

	/** Returns {@link Double#NaN}. */
	@Override
	public double getNeutralElement() {
		return Double.NaN;
	}
}