Author: erans Date: Sat Jun 2 17:53:05 2012 New Revision: 1345538 URL: http://svn.apache.org/viewvc?rev=1345538&view=rev Log: MATH-798 Test case provided by the reporter, adapted to become a unit test, shows that the same convergence criterion generates a very similar solution by both "LevenbergMarquardtOptimizer" and "GaussNewtonOptimizer".
Modified: commons/proper/math/trunk/src/test/java/org/apache/commons/math3/optimization/fitting/CurveFitterTest.java Modified: commons/proper/math/trunk/src/test/java/org/apache/commons/math3/optimization/fitting/CurveFitterTest.java URL: http://svn.apache.org/viewvc/commons/proper/math/trunk/src/test/java/org/apache/commons/math3/optimization/fitting/CurveFitterTest.java?rev=1345538&r1=1345537&r2=1345538&view=diff ============================================================================== --- commons/proper/math/trunk/src/test/java/org/apache/commons/math3/optimization/fitting/CurveFitterTest.java (original) +++ commons/proper/math/trunk/src/test/java/org/apache/commons/math3/optimization/fitting/CurveFitterTest.java Sat Jun 2 17:53:05 2012 @@ -18,8 +18,13 @@ package org.apache.commons.math3.optimization.fitting; import org.apache.commons.math3.optimization.general.LevenbergMarquardtOptimizer; +import org.apache.commons.math3.optimization.general.GaussNewtonOptimizer; +import org.apache.commons.math3.optimization.DifferentiableMultivariateVectorOptimizer; +import org.apache.commons.math3.optimization.SimpleVectorValueChecker; import org.apache.commons.math3.analysis.ParametricUnivariateFunction; +import org.apache.commons.math3.analysis.polynomials.PolynomialFunction; import org.apache.commons.math3.util.FastMath; +import org.apache.commons.math3.util.Precision; import org.junit.Assert; import org.junit.Test; @@ -133,6 +138,69 @@ public class CurveFitterTest { } + @Test + public void testMath798() { + final double tol = 1e-14; + final SimpleVectorValueChecker checker = new SimpleVectorValueChecker(tol, tol); + final double[] init = new double[] { 0, 0 }; + final int maxEval = 3; + + final double[] lm = doMath798(new LevenbergMarquardtOptimizer(checker), maxEval, init); + final double[] gn = doMath798(new GaussNewtonOptimizer(checker), maxEval, init); + + for (int i = 0; i <= 1; i++) { + Assert.assertEquals(lm[i], gn[i], tol); + } + } + + /** + * @param optimizer Optimizer. + * @param maxEval Maximum number of function evaluations. + * @param init First guess. + * @return the solution found by the given optimizer. + */ + private double[] doMath798(DifferentiableMultivariateVectorOptimizer optimizer, + int maxEval, + double[] init) { + final CurveFitter fitter = new CurveFitter(optimizer); + + fitter.addObservedPoint(-0.2, -7.12442E-13); + fitter.addObservedPoint(-0.199, -4.33397E-13); + fitter.addObservedPoint(-0.198, -2.823E-13); + fitter.addObservedPoint(-0.197, -1.40405E-13); + fitter.addObservedPoint(-0.196, -7.80821E-15); + fitter.addObservedPoint(-0.195, 6.20484E-14); + fitter.addObservedPoint(-0.194, 7.24673E-14); + fitter.addObservedPoint(-0.193, 1.47152E-13); + fitter.addObservedPoint(-0.192, 1.9629E-13); + fitter.addObservedPoint(-0.191, 2.12038E-13); + fitter.addObservedPoint(-0.19, 2.46906E-13); + fitter.addObservedPoint(-0.189, 2.77495E-13); + fitter.addObservedPoint(-0.188, 2.51281E-13); + fitter.addObservedPoint(-0.187, 2.64001E-13); + fitter.addObservedPoint(-0.186, 2.8882E-13); + fitter.addObservedPoint(-0.185, 3.13604E-13); + fitter.addObservedPoint(-0.184, 3.14248E-13); + fitter.addObservedPoint(-0.183, 3.1172E-13); + fitter.addObservedPoint(-0.182, 3.12912E-13); + fitter.addObservedPoint(-0.181, 3.06761E-13); + fitter.addObservedPoint(-0.18, 2.8559E-13); + fitter.addObservedPoint(-0.179, 2.86806E-13); + fitter.addObservedPoint(-0.178, 2.985E-13); + fitter.addObservedPoint(-0.177, 2.67148E-13); + fitter.addObservedPoint(-0.176, 2.94173E-13); + fitter.addObservedPoint(-0.175, 3.27528E-13); + fitter.addObservedPoint(-0.174, 3.33858E-13); + fitter.addObservedPoint(-0.173, 2.97511E-13); + fitter.addObservedPoint(-0.172, 2.8615E-13); + fitter.addObservedPoint(-0.171, 2.84624E-13); + + final double[] coeff = fitter.fit(maxEval, + new PolynomialFunction.Parametric(), + init); + return coeff; + } + private static class SimpleInverseFunction implements ParametricUnivariateFunction { public double value(double x, double ... parameters) {