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.MatrixUtils; 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 final int dim = weight.length; 043 weightMatrix = MatrixUtils.createRealMatrix(dim, dim); 044 for (int i = 0; i < dim; i++) { 045 weightMatrix.setEntry(i, i, weight[i]); 046 } 047 } 048 049 /** 050 * @param weight Weight matrix. 051 * @throws NonSquareMatrixException if the argument is not 052 * a square matrix. 053 */ 054 public Weight(RealMatrix weight) { 055 if (weight.getColumnDimension() != weight.getRowDimension()) { 056 throw new NonSquareMatrixException(weight.getColumnDimension(), 057 weight.getRowDimension()); 058 } 059 060 weightMatrix = weight.copy(); 061 } 062 063 /** 064 * Gets the initial guess. 065 * 066 * @return the initial guess. 067 */ 068 public RealMatrix getWeight() { 069 return weightMatrix.copy(); 070 } 071 }