/*
 * 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.commons.math.optimization.fitting;

import java.io.Serializable;

/**
 * This class is a simple container for weighted observed point in
 * {@link CurveFitter curve fitting}.
 * <p>
 * Instances of this class are guaranteed to be immutable.
 * </p>
 * 
 * @version $Revision$ $Date$
 * @since 2.0
 */
public class WeightedObservedPoint implements Serializable {

	/** Serializable version id. */
	private static final long serialVersionUID = 5306874947404636157L;

	/** Weight of the measurement in the fitting process. */
	private final double weight;

	/** Abscissa of the point. */
	private final double x;

	/** Observed value of the function at x. */
	private final double y;

	/**
	 * Simple constructor.
	 * 
	 * @param weight
	 *            weight of the measurement in the fitting process
	 * @param x
	 *            abscissa of the measurement
	 * @param y
	 *            ordinate of the measurement
	 */
	public WeightedObservedPoint(final double weight, final double x, final double y) {
		this.weight = weight;
		this.x = x;
		this.y = y;
	}

	/**
	 * Get the weight of the measurement in the fitting process.
	 * 
	 * @return weight of the measurement in the fitting process
	 */
	public double getWeight() {
		return weight;
	}

	/**
	 * Get the abscissa of the point.
	 * 
	 * @return abscissa of the point
	 */
	public double getX() {
		return x;
	}

	/**
	 * Get the observed value of the function at x.
	 * 
	 * @return observed value of the function at x
	 */
	public double getY() {
		return y;
	}

}
