Distribution.h

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/*
 * 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) 1999-2009 Soeren Sonnenburg
 * Written (W) 2014 Parijat Mazumdar
 * Copyright (C) 1999-2009 Fraunhofer Institute FIRST and Max-Planck-Society
 */

#ifndef _DISTRIBUTION_H___
#define _DISTRIBUTION_H___

#include <shogun/lib/config.h>

#include <shogun/features/Features.h>
#include <shogun/mathematics/Math.h>
#include <shogun/base/SGObject.h>

namespace shogun
{
class CFeatures;
class CMath;
class CDistribution : public CSGObject
{
    public:
        CDistribution();

        virtual ~CDistribution();

        virtual bool train(CFeatures* data=NULL)=0;

        virtual int32_t get_num_model_parameters()=0;

        virtual int32_t get_num_relevant_model_parameters();

        virtual float64_t get_log_model_parameter(int32_t num_param)=0;

        virtual float64_t get_log_derivative(
            int32_t num_param, int32_t num_example)=0;

        virtual float64_t get_log_likelihood_example(int32_t num_example)=0;

        virtual float64_t get_log_likelihood_sample();

        virtual SGVector<float64_t> get_log_likelihood();

        virtual float64_t get_model_parameter(int32_t num_param)
        {
            return exp(get_log_model_parameter(num_param));
        }

        virtual float64_t get_derivative(
            int32_t num_param, int32_t num_example)
        {
            return exp(get_log_derivative(num_param, num_example));
        }

        virtual float64_t get_likelihood_example(int32_t num_example)
        {
            return exp(get_log_likelihood_example(num_example));
        }

        virtual SGVector<float64_t> get_likelihood_for_all_examples();

        virtual void set_features(CFeatures* f)
        {
            SG_UNREF(features);
            features=f;
            SG_REF(features);
        }

        virtual CFeatures* get_features()
        {
            SG_REF(features);
            return features;
        }

        virtual void set_pseudo_count(float64_t pseudo) { pseudo_count=pseudo; }

        virtual float64_t get_pseudo_count() { return pseudo_count; }

        virtual float64_t update_params_em(float64_t* alpha_k, int32_t len);

        static CDistribution* obtain_from_generic(CSGObject* object);

    protected:
        CFeatures* features;
        float64_t pseudo_count;
};
}
#endif