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Add IMinimizer interface so that same curve fitting approach can be used for any function minimization algorithm.pull/173/head
7 changed files with 180 additions and 51 deletions
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// <copyright file="IMinimizer.cs" company="Math.NET">
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// Math.NET Numerics, part of the Math.NET Project
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// http://numerics.mathdotnet.com
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// http://github.com/mathnet/mathnet-numerics
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// http://mathnetnumerics.codeplex.com
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//
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// Copyright (c) 2009-2010 Math.NET
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//
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// Permission is hereby granted, free of charge, to any person
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// obtaining a copy of this software and associated documentation
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// files (the "Software"), to deal in the Software without
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// restriction, including without limitation the rights to use,
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// copy, modify, merge, publish, distribute, sublicense, and/or sell
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// copies of the Software, and to permit persons to whom the
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// Software is furnished to do so, subject to the following
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// conditions:
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//
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// The above copyright notice and this permission notice shall be
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// included in all copies or substantial portions of the Software.
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//
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// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
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// EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES
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// OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
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// NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT
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// HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY,
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// WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
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// FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
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// OTHER DEALINGS IN THE SOFTWARE.
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// </copyright>
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namespace MathNet.Numerics.Optimization |
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{ |
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using System; |
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/// <summary>
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/// Interface implemented by a class that minimizes f(p) where p is a vector of model parameters.
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/// A class implenting this interface can then be used to solve curve fitting problems.
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/// </summary>
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public interface IMinimizer |
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{ |
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double[] Minimize(Func<double[], double> function, double[] pInitialGuess); |
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} |
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public static class NonLinearCurveFitExtensions |
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{ |
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/// <summary>
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/// Non-Linear Least-Squares fitting the points (x,y) to a specified function of y : x -> f(x, p), p being a vector of parameters.
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/// returning its best fitting parameters p.
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/// </summary>
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/// <param name="x"></param>
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/// <param name="y"></param>
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/// <param name="f"></param>
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/// <param name="pStart">Initial guess of parameters, p.</param>
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/// <returns></returns>
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public static double[] CurveFit(this IMinimizer minimizer, double[] x, double[] y, Func<double, double[], double> f, |
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double[] pStart) |
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{ |
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// Need to minimize sum of squares of residuals; create this function:
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Func<double[], double> function = (p) => |
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{ |
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double sum = 0; |
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for (int i = 0; i < x.Length; ++i) |
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{ |
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double temp = y[i] - f(x[i], p); |
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sum += temp * temp; |
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} |
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return sum; |
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}; |
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return minimizer.Minimize(function, pStart); |
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} |
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} |
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} |
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