Java tutorial
/* * 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.math3.fitting.leastsquares; import org.apache.commons.math3.analysis.MultivariateMatrixFunction; import org.apache.commons.math3.analysis.MultivariateVectorFunction; import org.apache.commons.math3.fitting.leastsquares.LeastSquaresProblem.Evaluation; import org.apache.commons.math3.linear.ArrayRealVector; import org.apache.commons.math3.linear.RealMatrix; import org.apache.commons.math3.linear.RealVector; import org.apache.commons.math3.optim.ConvergenceChecker; import org.apache.commons.math3.optim.PointVectorValuePair; /** * A mutable builder for {@link LeastSquaresProblem}s. * * @see LeastSquaresFactory * @since 3.3 */ public class LeastSquaresBuilder { /** max evaluations */ private int maxEvaluations; /** max iterations */ private int maxIterations; /** convergence checker */ private ConvergenceChecker<Evaluation> checker; /** model function */ private MultivariateJacobianFunction model; /** observed values */ private RealVector target; /** initial guess */ private RealVector start; /** weight matrix */ private RealMatrix weight; /** * Lazy evaluation. * * @since 3.4 */ private boolean lazyEvaluation; /** Validator. * * @since 3.4 */ private ParameterValidator paramValidator; /** * Construct a {@link LeastSquaresProblem} from the data in this builder. * * @return a new {@link LeastSquaresProblem}. */ public LeastSquaresProblem build() { return LeastSquaresFactory.create(model, target, start, weight, checker, maxEvaluations, maxIterations, lazyEvaluation, paramValidator); } /** * Configure the max evaluations. * * @param newMaxEvaluations the maximum number of evaluations permitted. * @return this */ public LeastSquaresBuilder maxEvaluations(final int newMaxEvaluations) { this.maxEvaluations = newMaxEvaluations; return this; } /** * Configure the max iterations. * * @param newMaxIterations the maximum number of iterations permitted. * @return this */ public LeastSquaresBuilder maxIterations(final int newMaxIterations) { this.maxIterations = newMaxIterations; return this; } /** * Configure the convergence checker. * * @param newChecker the convergence checker. * @return this */ public LeastSquaresBuilder checker(final ConvergenceChecker<Evaluation> newChecker) { this.checker = newChecker; return this; } /** * Configure the convergence checker. * <p/> * This function is an overloaded version of {@link #checker(ConvergenceChecker)}. * * @param newChecker the convergence checker. * @return this */ public LeastSquaresBuilder checkerPair(final ConvergenceChecker<PointVectorValuePair> newChecker) { return this.checker(LeastSquaresFactory.evaluationChecker(newChecker)); } /** * Configure the model function. * * @param value the model function value * @param jacobian the Jacobian of {@code value} * @return this */ public LeastSquaresBuilder model(final MultivariateVectorFunction value, final MultivariateMatrixFunction jacobian) { return model(LeastSquaresFactory.model(value, jacobian)); } /** * Configure the model function. * * @param newModel the model function value and Jacobian * @return this */ public LeastSquaresBuilder model(final MultivariateJacobianFunction newModel) { this.model = newModel; return this; } /** * Configure the observed data. * * @param newTarget the observed data. * @return this */ public LeastSquaresBuilder target(final RealVector newTarget) { this.target = newTarget; return this; } /** * Configure the observed data. * * @param newTarget the observed data. * @return this */ public LeastSquaresBuilder target(final double[] newTarget) { return target(new ArrayRealVector(newTarget, false)); } /** * Configure the initial guess. * * @param newStart the initial guess. * @return this */ public LeastSquaresBuilder start(final RealVector newStart) { this.start = newStart; return this; } /** * Configure the initial guess. * * @param newStart the initial guess. * @return this */ public LeastSquaresBuilder start(final double[] newStart) { return start(new ArrayRealVector(newStart, false)); } /** * Configure the weight matrix. * * @param newWeight the weight matrix * @return this */ public LeastSquaresBuilder weight(final RealMatrix newWeight) { this.weight = newWeight; return this; } /** * Configure whether evaluation will be lazy or not. * * @param newValue Whether to perform lazy evaluation. * @return this object. * * @since 3.4 */ public LeastSquaresBuilder lazyEvaluation(final boolean newValue) { lazyEvaluation = newValue; return this; } /** * Configure the validator of the model parameters. * * @param newValidator Parameter validator. * @return this object. * * @since 3.4 */ public LeastSquaresBuilder parameterValidator(final ParameterValidator newValidator) { paramValidator = newValidator; return this; } }