/* * 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}). *
* Usage example: *
* 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(); ** * @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 (
x
, y
) to list of observed points
* with a weight of 1.0.
*
* @param x x point value
* @param y y point value
*/
public void addObservedPoint(double x, double y) {
addObservedPoint(1.0, x, y);
}
/**
* Adds point (x
, y
) to list of observed points
* with a weight of weight
.
*
* @param weight weight assigned to point
* @param x x point value
* @param y y 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 CurveFitter.fit
throws it
* @throws OptimizationException if CurveFitter.fit
throws it
* @throws IllegalArgumentException if CurveFitter.fit
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 GaussianParametersGuesser
* instance initialized with the specified observations.
*
* @param observations points used to initialize the created
* GaussianParametersGuesser
instance
*
* @return new GaussianParametersGuesser
instance
*/
protected GaussianParametersGuesser createParametersGuesser(WeightedObservedPoint[] observations) {
return new GaussianParametersGuesser(observations);
}
}