// <copyright file="GradientObjectiveFunction.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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//
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// Copyright (c) 2009-2017 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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using System;
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using IStation.Numerics.LinearAlgebra;
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namespace IStation.Numerics.Optimization.ObjectiveFunctions
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{
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internal class GradientObjectiveFunction : IObjectiveFunction
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{
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readonly Func<Vector<double>, Tuple<double, Vector<double>>> _function;
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public GradientObjectiveFunction(Func<Vector<double>, Tuple<double, Vector<double>>> function)
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{
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_function = function;
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}
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public IObjectiveFunction CreateNew()
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{
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return new GradientObjectiveFunction(_function);
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}
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public IObjectiveFunction Fork()
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{
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// no need to deep-clone values since they are replaced on evaluation
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return new GradientObjectiveFunction(_function)
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{
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Point = Point,
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Value = Value,
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Gradient = Gradient
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};
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}
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public bool IsGradientSupported => true;
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public bool IsHessianSupported => false;
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public void EvaluateAt(Vector<double> point)
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{
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Point = point;
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var result = _function(point);
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Value = result.Item1;
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Gradient = result.Item2;
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}
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public Vector<double> Point { get; private set; }
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public double Value { get; private set; }
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public Vector<double> Gradient { get; private set; }
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public Matrix<double> Hessian => throw new NotSupportedException();
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}
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}
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