StreamingDenseDataGenerator.cpp

/*
 * 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 Heiko Strathmann
 */

#include <shogun/features/streaming/StreamingDenseDataGenerator.h>

using namespace shogun;

template<class T>
CStreamingDenseDataGenerator<T>::CStreamingDenseDataGenerator() :
        CStreamingDenseDataGenerator<T>()
{
    init();
}

template<class T>
CStreamingDenseDataGenerator<T>::~CStreamingDenseDataGenerator()
{
    delete m_model_parameters;
}

template<class T>
void CStreamingDenseDataGenerator<T>::init()
{
    m_model_parameters=new Parameter();
    m_model=DGD_NONE;
}

template<class T>
void CStreamingDenseDataGenerator<T>::set_mean_shift_model(T mean_shift,
        index_t dim)
{
    /* re-create parmeter list and add specified parameters */
    delete m_model_parameters();
    m_model_parameters=new Parameter();
    m_model_parameters->add(&mean_shift, "mean_shift");
    m_model_parameters->add(&dim, "dim");

    m_model=DGD_MEAN_SHIFT;
}

template<class T>
SGVector<T> CStreamingDenseDataGenerator<T>::generate_mean_shift_data(
        index_t dim, T mean_shift)
{
    /* allocate space */
    SGVector<T> result=SGVector<T>(dim);

    /* fill with std normal data */
    for (index_t i=0; i<dim; ++i)
        result[i]=CMath::randn_double();

    /* mean shift in first dimension */
    result[0]+=mean_shift;

    return result;
}

template<class T>
bool CStreamingDenseDataGenerator<T>::get_next_example()
{
    bool result=true;

    /* these casts are safe due to the way the parameters were added above */
    switch (m_model)
        {
        case DGD_MEAN_SHIFT:
            T mean_shift=*((T*)
                    (m_model_parameters->get_parameter("mean_shift")->m_parameter));
            index_t dim=*((index_t*)
                    (m_model_parameters->get_parameter("dim")->m_parameter));

            CStreamingDenseDataGenerator<T>::current_vector=
                    generate_mean_shift_data(dim, mean_shift);
            break;
        default:
            SG_SWARNING("%s::get_streamed_features(): no model specified!");
            result=false;
            break;
        }

    return result;
}