Files
jube-fork/Accord.Math/Distances/WeightedSquareEuclidean.cs
richard-churchman cc0a2bee21 Extensive modifications to the serialisation of Neural Network models to support Newtonsoft Json.net rather than Binary Serializer.
Included open-source Accord.net library code natively to the solution given the deprecated state of that project.  Accord.net will be supported inside Jube for own needs (such as upgrading to .Net 7+).

Accord.net libraries modified to compile to .Net 6.

Modified Accord.net libraries to better support Newtonsoft Json.net serialisation.

Included annotations in the Accord.net libraries to house important dependency statistics. Serialised json can be used independently of Jube to recall a Neural Network.

Removal of Binary Serializer totally as a precursor to the projects support of .Net 7+.

Extensive bug fixing in crucial functions of Neural Network training and recall.  While this part of the system remains in Alpha, it is substantially more fit for purpose.
2023-12-24 10:22:22 +01:00

126 lines
4.3 KiB
C#

// Accord Math Library
// The Accord.NET Framework
// http://accord-framework.net
//
// Copyright © César Souza, 2009-2017
// cesarsouza at gmail.com
//
// This library is free software; you can redistribute it and/or
// modify it under the terms of the GNU Lesser General Public
// License as published by the Free Software Foundation; either
// version 2.1 of the License, or (at your option) any later version.
//
// This library is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
// Lesser General Public License for more details.
//
// You should have received a copy of the GNU Lesser General Public
// License along with this library; if not, write to the Free Software
// Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
//
namespace Accord.Math.Distances
{
using System;
using System.Runtime.CompilerServices;
using Accord.Compat;
/// <summary>
/// Weighted Square-Euclidean distance and similarity. Please note that this
/// distance is not a metric as it doesn't obey the triangle inequality.
/// </summary>
///
/// <seealso cref="Euclidean"/>
/// <seealso cref="WeightedEuclidean"/>
/// <seealso cref="WeightedSquareEuclidean"/>
///
[Serializable]
public struct WeightedSquareEuclidean : IDistance<double[]>, ISimilarity<double[]>, ICloneable
{
private double[] weights;
/// <summary>
/// Gets or sets the weights for each dimension. Default is a vector of ones.
/// </summary>
///
/// <value>The weights.</value>
///
public double[] Weights
{
get { return weights; }
set { weights = value; }
}
/// <summary>
/// Initializes a new instance of the <see cref="WeightedSquareEuclidean"/> struct.
/// </summary>
/// <param name="dimensions">The number of dimensions (columns) in the dataset.</param>
public WeightedSquareEuclidean(int dimensions)
{
this.weights = Vector.Ones(dimensions);
}
/// <summary>
/// Initializes a new instance of the <see cref="WeightedSquareEuclidean"/> struct.
/// </summary>
/// <param name="weights">The weights.</param>
public WeightedSquareEuclidean(double[] weights)
{
this.weights = weights;
}
/// <summary>
/// Computes the distance <c>d(x,y)</c> between points
/// <paramref name="x"/> and <paramref name="y"/>.
/// </summary>
///
/// <param name="x">The first point <c>x</c>.</param>
/// <param name="y">The second point <c>y</c>.</param>
///
/// <returns>
/// A double-precision value representing the distance <c>d(x,y)</c>
/// between <paramref name="x"/> and <paramref name="y"/> according
/// to the distance function implemented by this class.
/// </returns>
///
#if NET45 || NET46 || NET462 || NETSTANDARD2_0
[MethodImpl(MethodImplOptions.AggressiveInlining)]
#endif
public double Distance(double[] x, double[] y)
{
double sum = 0.0;
for (int i = 0; i < x.Length; i++)
{
double u = x[i] - y[i];
sum += u * u * weights[i];
}
return sum;
}
/// <summary>
/// Gets a similarity measure between two points.
/// </summary>
///
/// <param name="x">The first point to be compared.</param>
/// <param name="y">The second point to be compared.</param>
///
/// <returns>A similarity measure between x and y.</returns>
///
public double Similarity(double[] x, double[] y)
{
return 1.0 / (1.0 + Distance(x, y));
}
/// <summary>
/// Creates a new object that is a copy of the current instance.
/// </summary>
/// <returns>A new object that is a copy of this instance.</returns>
public object Clone()
{
return new WeightedSquareEuclidean((double[])weights.Clone());
}
}
}