﻿// Accord Math Library
// The Accord.NET Framework
// http://accord-framework.net
//
// Copyright © César Souza, 2009-2016
// 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
{
    /// <summary>
    ///   Common interface for similarity measures.
    /// </summary>
    /// 
    /// <typeparam name="T">The type of the first element to be compared.</typeparam>
    /// <typeparam name="U">The type of the second element to be compared.</typeparam>
    /// 
    public interface ISimilarity<T, U>
    {
        /// <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>
        /// 
        double Similarity(T x, U y);
    }

    /// <summary>
    ///   Common interface for similarity measures.
    /// </summary>
    /// 
    /// <typeparam name="T">The type of the elements to be compared.</typeparam>
    /// 
    public interface ISimilarity<T> : ISimilarity<T, T>
    {

    }
}
