Files
lms/src/similarity/features/som/Network.hpp
T

112 lines
3.6 KiB
C++

/*
* Copyright (C) 2018 Emeric Poupon
*
* This file is part of LMS.
*
* LMS is free software: you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation, either version 3 of the License, or
* (at your option) any later version.
*
* LMS 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 General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with LMS. If not, see <http://www.gnu.org/licenses/>.
*/
#pragma once
#include <vector>
#include <set>
#include <ostream>
#include <functional>
#include <boost/optional.hpp>
#include "Matrix.hpp"
#include "utils/Exception.hpp"
namespace SOM
{
using InputVector = std::vector<double>;
void checkSameDimensions(const InputVector& a, const InputVector& b);
void checkSameDimensions(const InputVector& a, std::size_t inputDimCount);
std::ostream& operator<<(std::ostream& os, const InputVector& a);
class SOMException : public LmsException
{
public:
SOMException(const std::string& msg) : LmsException(msg) {}
};
class Network
{
public:
// Init a network with random values
Network(std::size_t width, std::size_t height, std::size_t inputDimCount);
// Init a network with serialized values
Network(const std::string& data);
std::size_t getWidth() const { return _refVectors.getWidth(); }
std::size_t getHeight() const { return _refVectors.getHeight(); }
std::size_t getInputDimCount() const {return _inputDimCount;}
// Set weight for each dimension (default is 1 for each weight)
void setDataWeights(const InputVector& weights);
// <!> data must be normalized
void train(const std::vector<InputVector>& dataSamples, std::size_t nbIterations);
Coords getClosestRefVectorCoords(const InputVector& data) const;
boost::optional<Coords> getClosestRefVectorCoords(const InputVector& data, double maxDistance) const;
boost::optional<Coords> getClosestRefVectorCoords(const std::set<Coords>& refVectorsCoords, double maxDistance) const;
double getRefVectorsDistance(Coords coords1, Coords coords2) const;
double computeRefVectorsDistanceMean() const;
double computeRefVectorsDistanceMedian() const;
void dump(std::ostream& os) const;
// For each ref vector, update formula is:
// i is the current iteration
// refVector(i+1) = refVector(i) + LearningFactor(i) * NeighbourhoodFunc(i) * (MatchingRefVector - refVector)
using DistanceFunc = std::function<InputVector::value_type(const InputVector& /* a */, const InputVector& /* b */, const InputVector& /* weights */)>;
void setDistanceFunc(DistanceFunc distanceFunc);
struct CurrentIteration
{
std::size_t idIteration;
std::size_t iterationCount;
};
using LearningFactorFunc = std::function<InputVector::value_type(CurrentIteration)>;
void setLearningFactorFunc(LearningFactorFunc learningFactorFunc);
using NeighbourhoodFunc = std::function<InputVector::value_type(InputVector::value_type /* norm(Coords - CoordMatchingRefVector) */, CurrentIteration)>;
void setNeighbourhoodFunc(NeighbourhoodFunc neighbourhoodFunc);
private:
void updateRefVectors(Coords closestRefVectorCoords, const InputVector& input, CurrentIteration iteration);
std::size_t _inputDimCount;
InputVector _weights; // weight for each dimension
Matrix<InputVector> _refVectors;
DistanceFunc _distanceFunc;
LearningFactorFunc _learningFactorFunc;
NeighbourhoodFunc _neighbourhoodFunc;
};
} // namespace SOM