/*
 * 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;

import java.io.Serializable;

import org.apache.commons.math.analysis.MultivariateRealFunction;

/**
 * This class holds a point and the value of an objective function at this
 * point.
 * <p>
 * This is a simple immutable container.
 * </p>
 * 
 * @see VectorialPointValuePair
 * @see MultivariateRealFunction
 * @version $Revision$ $Date$
 * @since 2.0
 */
public class RealPointValuePair implements Serializable {

	/** Serializable version identifier. */
	private static final long serialVersionUID = 1003888396256744753L;

	/** Point coordinates. */
	private final double[] point;

	/** Value of the objective function at the point. */
	private final double value;

	/**
	 * Build a point/objective function value pair.
	 * 
	 * @param point
	 *            point coordinates (the built instance will store a copy of the
	 *            array, not the array passed as argument)
	 * @param value
	 *            value of an objective function at the point
	 */
	public RealPointValuePair(final double[] point, final double value) {
		this.point = point.clone();
		this.value = value;
	}

	/**
	 * Build a point/objective function value pair.
	 * 
	 * @param point
	 *            point coordinates (the built instance will store a copy of the
	 *            array, not the array passed as argument)
	 * @param value
	 *            value of an objective function at the point
	 * @param copyArray
	 *            if true, the input array will be copied, otherwise it will be
	 *            referenced
	 */
	public RealPointValuePair(final double[] point, final double value, final boolean copyArray) {
		this.point = copyArray ? point.clone() : point;
		this.value = value;
	}

	/**
	 * Get the point.
	 * 
	 * @return a copy of the stored point
	 */
	public double[] getPoint() {
		return point.clone();
	}

	/**
	 * Get a reference to the point.
	 * <p>
	 * This method is provided as a convenience to avoid copying the array, the
	 * elements of the array should <em>not</em> be modified.
	 * </p>
	 * 
	 * @return a reference to the internal array storing the point
	 */
	public double[] getPointRef() {
		return point;
	}

	/**
	 * Get the value of the objective function.
	 * 
	 * @return the stored value of the objective function
	 */
	public double getValue() {
		return value;
	}

}
