001 /*
002 * Licensed to the Apache Software Foundation (ASF) under one or more
003 * contributor license agreements. See the NOTICE file distributed with
004 * this work for additional information regarding copyright ownership.
005 * The ASF licenses this file to You under the Apache License, Version 2.0
006 * (the "License"); you may not use this file except in compliance with
007 * the License. You may obtain a copy of the License at
008 *
009 * http://www.apache.org/licenses/LICENSE-2.0
010 *
011 * Unless required by applicable law or agreed to in writing, software
012 * distributed under the License is distributed on an "AS IS" BASIS,
013 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
014 * See the License for the specific language governing permissions and
015 * limitations under the License.
016 */
017 package org.apache.commons.math3.optim.nonlinear.vector;
018
019 import org.apache.commons.math3.optim.OptimizationData;
020 import org.apache.commons.math3.linear.RealMatrix;
021 import org.apache.commons.math3.linear.DiagonalMatrix;
022 import org.apache.commons.math3.linear.NonSquareMatrixException;
023
024 /**
025 * Weight matrix of the residuals between model and observations.
026 * <br/>
027 * Immutable class.
028 *
029 * @version $Id: Weight.java 1416643 2012-12-03 19:37:14Z tn $
030 * @since 3.1
031 */
032 public class Weight implements OptimizationData {
033 /** Weight matrix. */
034 private final RealMatrix weightMatrix;
035
036 /**
037 * Creates a diagonal weight matrix.
038 *
039 * @param weight List of the values of the diagonal.
040 */
041 public Weight(double[] weight) {
042 weightMatrix = new DiagonalMatrix(weight);
043 }
044
045 /**
046 * @param weight Weight matrix.
047 * @throws NonSquareMatrixException if the argument is not
048 * a square matrix.
049 */
050 public Weight(RealMatrix weight) {
051 if (weight.getColumnDimension() != weight.getRowDimension()) {
052 throw new NonSquareMatrixException(weight.getColumnDimension(),
053 weight.getRowDimension());
054 }
055
056 weightMatrix = weight.copy();
057 }
058
059 /**
060 * Gets the initial guess.
061 *
062 * @return the initial guess.
063 */
064 public RealMatrix getWeight() {
065 return weightMatrix.copy();
066 }
067 }