| /* |
| * 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 org.apache.commons.math.FunctionEvaluationException; |
| import org.apache.commons.math.optimization.DifferentiableMultivariateVectorialOptimizer; |
| import org.apache.commons.math.optimization.OptimizationException; |
| import org.apache.commons.math.optimization.fitting.CurveFitter; |
| import org.apache.commons.math.optimization.fitting.WeightedObservedPoint; |
| |
| /** |
| * Fits points to a Gaussian function (that is, a {@link GaussianFunction}). |
| * <p> |
| * Usage example: |
| * <pre> |
| * GaussianFitter fitter = new GaussianFitter( |
| * new LevenbergMarquardtOptimizer()); |
| * fitter.addObservedPoint(4.0254623, 531026.0); |
| * fitter.addObservedPoint(4.03128248, 984167.0); |
| * fitter.addObservedPoint(4.03839603, 1887233.0); |
| * fitter.addObservedPoint(4.04421621, 2687152.0); |
| * fitter.addObservedPoint(4.05132976, 3461228.0); |
| * fitter.addObservedPoint(4.05326982, 3580526.0); |
| * fitter.addObservedPoint(4.05779662, 3439750.0); |
| * fitter.addObservedPoint(4.0636168, 2877648.0); |
| * fitter.addObservedPoint(4.06943698, 2175960.0); |
| * fitter.addObservedPoint(4.07525716, 1447024.0); |
| * fitter.addObservedPoint(4.08237071, 717104.0); |
| * fitter.addObservedPoint(4.08366408, 620014.0); |
| * GaussianFunction fitFunction = fitter.fit(); |
| * </pre> |
| * |
| * @see ParametricGaussianFunction |
| * @since 2.2 |
| * @version $Revision: 1073158 $ $Date: 2011-02-21 22:46:52 +0100 (lun. 21 févr. 2011) $ |
| */ |
| public class GaussianFitter { |
| |
| /** Fitter used for fitting. */ |
| private final CurveFitter fitter; |
| |
| /** |
| * Constructs an instance using the specified optimizer. |
| * |
| * @param optimizer optimizer to use for the fitting |
| */ |
| public GaussianFitter(DifferentiableMultivariateVectorialOptimizer optimizer) { |
| fitter = new CurveFitter(optimizer); |
| } |
| |
| /** |
| * Adds point (<code>x</code>, <code>y</code>) to list of observed points |
| * with a weight of 1.0. |
| * |
| * @param x <tt>x</tt> point value |
| * @param y <tt>y</tt> point value |
| */ |
| public void addObservedPoint(double x, double y) { |
| addObservedPoint(1.0, x, y); |
| } |
| |
| /** |
| * Adds point (<code>x</code>, <code>y</code>) to list of observed points |
| * with a weight of <code>weight</code>. |
| * |
| * @param weight weight assigned to point |
| * @param x <tt>x</tt> point value |
| * @param y <tt>y</tt> point value |
| */ |
| public void addObservedPoint(double weight, double x, double y) { |
| fitter.addObservedPoint(weight, x, y); |
| } |
| |
| /** |
| * Fits Gaussian function to the observed points. |
| * |
| * @return Gaussian function best fitting the observed points |
| * |
| * @throws FunctionEvaluationException if <code>CurveFitter.fit</code> throws it |
| * @throws OptimizationException if <code>CurveFitter.fit</code> throws it |
| * @throws IllegalArgumentException if <code>CurveFitter.fit</code> throws it |
| * |
| * @see CurveFitter |
| */ |
| public GaussianFunction fit() throws FunctionEvaluationException, OptimizationException { |
| return new GaussianFunction(fitter.fit(new ParametricGaussianFunction(), |
| createParametersGuesser(fitter.getObservations()).guess())); |
| } |
| |
| /** |
| * Factory method to create a <code>GaussianParametersGuesser</code> |
| * instance initialized with the specified observations. |
| * |
| * @param observations points used to initialize the created |
| * <code>GaussianParametersGuesser</code> instance |
| * |
| * @return new <code>GaussianParametersGuesser</code> instance |
| */ |
| protected GaussianParametersGuesser createParametersGuesser(WeightedObservedPoint[] observations) { |
| return new GaussianParametersGuesser(observations); |
| } |
| } |