drwnKMeans.h

/******************************************************************************
** DARWIN: A FRAMEWORK FOR MACHINE LEARNING RESEARCH AND DEVELOPMENT
** Distributed under the terms of the BSD license (see the LICENSE file)
** Copyright (c) 2007-2017, Stephen Gould
** All rights reserved.
**
******************************************************************************
** FILENAME:    drwnKMeans.h
** AUTHOR(S):   Stephen Gould <stephen.gould@anu.edu.au>
**
*****************************************************************************/

#pragma once

#include <vector>
#include <limits>

#include "Eigen/Core"

#include "drwnBase.h"
#include "drwnFeatureTransform.h"

using namespace std;
using namespace Eigen;

// drwnKMeans class -----------------------------------------------------------

class drwnKMeans : public drwnUnsupervisedTransform {
 public:
    static int DEFAULT_K;      
    static int MAX_ITERATIONS; 

 private:
    unsigned _numClusters;    
    MatrixXd _centroids;      
    VectorXd _cSqNorm;        

 public:
    drwnKMeans(unsigned k = DEFAULT_K);
    drwnKMeans(const drwnKMeans& ft);
    ~drwnKMeans();

    // access functions
    const char *type() const { return "drwnKMeans"; }
    drwnKMeans *clone() const { return new drwnKMeans(*this); }

    const MatrixXd& getCentroids() const { return _centroids; }

    // i/o
    void clear();
    bool save(drwnXMLNode& node) const;
    bool load(drwnXMLNode& node);

    // training
    using drwnUnsupervisedTransform::train;
    double train(const vector<vector<double> >& features);
    double train(const vector<vector<double> >& features, const vector<double>& weights);

    // evaluation
    using drwnFeatureTransform::transform;
    void transform(const vector<double>& x, vector<double>& y) const;
};