ECOCRandomSparseEncoder.h

Go to the documentation of this file.

/*
 * This program 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.
 *
 * Written (W) 2012 Chiyuan Zhang
 * Copyright (C) 2012 Chiyuan Zhang
 */

#ifndef ECOCRANDOMSPARSEENCODER_H__
#define ECOCRANDOMSPARSEENCODER_H__

#include <shogun/mathematics/Math.h>
#include <shogun/multiclass/ecoc/ECOCEncoder.h>

namespace shogun
{

class CECOCRandomSparseEncoder: public CECOCEncoder
{
public:
    CECOCRandomSparseEncoder(int32_t maxiter=10000, int32_t codelen=0,
            float64_t pzero=0.5, float64_t pposone=0.25, float64_t pnegone=0.25);

    virtual ~CECOCRandomSparseEncoder() {}

    void set_probability(float64_t pzero, float64_t pposone, float64_t pnegone);

    virtual const char* get_name() const { return "ECOCRandomSparseEncoder"; }

    int32_t get_default_code_length(int32_t num_classes) const
    {
        return static_cast<int32_t>(CMath::round(15 * CMath::log(num_classes)));
    }

    virtual SGMatrix<int32_t> create_codebook(int32_t num_classes);

protected:
    int32_t   m_maxiter;
    int32_t   m_codelen;
    float64_t m_pzero;
    float64_t m_pposone;
    float64_t m_pnegone;

private:
    bool check_probability(float64_t pzero, float64_t pposone, float64_t pnegone)
    {
        if (CMath::abs(pzero + pposone + pnegone - 1) > 1e-5)
            return false;
        return true;
    }

    void init();
};

} /* shogun */

#endif /* end of include guard: ECOCRANDOMSPARSEENCODER_H__ */