StreamingDenseDataGenerator.h

/*
 * 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
 */

#ifndef __STREAMINGDENSEDATAGENERATOR_H_
#define __STREAMINGDENSEDATAGENERATOR_H_

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

namespace shogun
{

enum EDenseDataGenerator
{
    DGD_NONE, DGD_MEAN_SHIFT, DGD_ROT_SYM_GAUSS
};

/** @brief
 * Class to generate dense features data via the streaming features interface.
 * The core are pairs of methods to
 * a) set the data model and parameters, and
 * b) to generate a data vector using these model parameters
 * Both methods are automatically called when calling get_next_example()
 * This allows to treat generated data as a stream via the standard streaming
 * features interface
 */
template <class T>
class CStreamingDenseDataGenerator: public CStreamingDenseFeatures<T>
{
public:
    /** Constructor */
    CStreamingDenseDataGenerator();

    /** Destructor */
    virtual ~CStreamingDenseDataGenerator();

    /** @return name of SG_SERIALIZABLE */
    inline virtual const char* get_name() const
    {
        return "StreamingDenseDataGenerator";
    }

    void set_mean_shift_model(T mean_shift, index_t dim);

    /** Takes a sample from two a distribution where each element
     * is standard normally distributed, except for the first dimension,
     * where the mean is shifted by a specified value.
     *
     * @param dim dimension of generated samples
     * @param mean_shift is added to mean of first dimension
     * @return dimx1 vector with sample
     */
    static SGVector<T> generate_mean_shift_data(index_t dim, T mean_shift);

    bool get_next_example();
private:
    /** registers all parameters and initializes variables with defaults */
    void init();

protected:
    /** model of data to generate */
    EDenseDataGenerator m_model;

    /** parameters of model */
    Parameter* m_model_parameters;
};

}

#endif /* __STREAMINGDENSEDATAGENERATOR_H_ */