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gnn_output.c

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/***************************************************************************
 *  @file gnn_output.c
 *  @brief Output Implementation.
 *
 *  @date   : 21-09-03 20:34
 *  @author : Pedro Ortega C. <peortega@dcc.uchile.cl>
 *  Copyright  2003  Pedro Ortega C.
 ****************************************************************************/
/*
 *  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 2 of the License, or
 *  (at your option) any later version.
 *
 *  This program is distributed in the hope that it will be useful,
 *  but WITHOUT ANY WARRANTY; without even the implied warranty of
 *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 *  GNU Library General Public License for more details.
 *
 *  You should have received a copy of the GNU General Public License
 *  along with this program; if not, write to the Free Software
 *  Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
 */



/**
 * @defgroup gnn_output_doc gnn_output : Writing sets of vectors.
 * @ingroup libgnn_dataset
 *
 * The \ref gnn_output type defines a common interface for vector sets
 * output handlers.
 *
 * \ref gnn_output datatypes are special objects that write vector samples
 * to output devices. The raw \ref gnn_output structure defines a common
 * interface that should be implemented by extensions of this type. Typical
 * implementations can write vectors to files, memory, ports, etc.
 *
 * There are two types of output devices: stream and random access. Stream
 * devices do print to an output stream without carying about the sample
 * and set size. In contrast, random access devices have a defined sample
 * and set size.
 */



/******************************************/
/* Include Files                          */
/******************************************/

#include "gnn_output.h"
#include "gnn_utilities.h"


/******************************************/
/* Static Declaration                     */
/******************************************/

static int
gnn_output_default_reset (gnn_output *set);

void
gnn_output_default_destroy (gnn_output *set);



/******************************************/
/* Static Implementation                  */
/******************************************/

/**
 * @brief Default "reset" function for a ouput writer.
 * @ingroup gnn_output_doc
 *
 * This function is the default "reset" function for an output set.
 * It does nothing.
 *
 * @param  set A pointer to a \ref gnn_output.
 * @return 0 if succeeded.
 */
static int
gnn_output_default_reset (gnn_output *set)
{
    assert (set != NULL);

    return 0;
}



/**
 * @brief Default "destroy" function for an output.
 * @ingroup gnn_output_doc
 *
 * This function is the default "destroy" function for an output. It assumes
 * that there isn't any additional data for the specific dataset type, so
 * it actually just returns.
 *
 * @param  set A pointer to a \ref gnn_output.
 */
void
gnn_output_default_destroy (gnn_output *set)
{
    return;
}



/******************************************/
/* Public Interface                       */
/******************************************/

/**
 * @brief Initializes a \ref gnn_output.
 * @ingroup gnn_output_doc
 *
 * This function initializes a given vector writer, setting its properties
 * and installing its functions.
 *
 * If the "reset", or "destroy" functions aren't provided, then the default
 * functions \ref gnn_output_default_reset and \ref gnn_output_default_destroy
 * are installed respectively. The "put" function is mandatory, and should
 * always be provided.
 *
 * As an example, suppose that you have made your own extension to the
 * \ref gnn_output datatype, one that writes to a random access file, which you
 * called "my_writer". Also, suppose you have already coded the
 * appropiate "reset", "put" and "destroy" functions for your special
 * writer. Then,
 * \code
   my_writer *myoutput; // a pointer to the output writer to be created
   gnn_output    *set;  // a pointer to the same structure, but viewed as a
                        // gnn_output

   // allocate memory for the output writer
   myoutput = (my_writer *) malloc (sizeof (my_writer));

   // view as a gnn_output
   set = (gnn_output *) myoutput;

   // initialize the output (you know there are only 100 samples)
   gnn_output_init (set, gnnOutputRA, 100, 5, serial_writer_reset,
                                              serial_writer_get,
                                              serial_writer_destroy);
 * \endcode
 * would initialize your output writer for 100 patterns, whose sample vectors
 * are of size 5.
 *
 * Please refer also to the alternative functions \ref gnn_output_stream_init
 * and \ref gnn_output_random_access_init.
 *
 * @param  set   A pointer to a \ref gnn_output.
 * @param  mode  Can be gnnOutputStream or gnnOutputRA.
 * @param  size  The number of samples that it contains.
 * @param  m     The size of the output samples.
 * @param  reset   A pointer to the output's "reset" function.
 * @param  put     A pointer to the output's "put" function.
 * @param  destroy A pointer to the output's "destroy" function.
 * @return 0 if succeeded.
 */
int
gnn_output_init (gnn_output     *set,
                 gnn_output_type mode,
                 size_t          size,
                 size_t          m,
                 gnn_output_reset_type   reset,
                 gnn_output_put_type     put,
                 gnn_output_destroy_type destroy)
{
    assert (set != NULL);

    /* check sizes */
    if (mode == gnnOutputRA && size < 1)
    {
        GSL_ERROR ("random access output sets should handle a stricly "
                   "positive number of samples", GSL_EINVAL);
    }
    if (mode == gnnOutputRA && m < 1)
    {
        GSL_ERROR ("random access output sets should have samples of stricly "
                   "positive number of vector elements", GSL_EINVAL);
    }

    /* check get function */
    if (put == NULL)
    {
        GSL_ERROR ("the \"put\" function is mandatory and should be provided",
                   GSL_EINVAL);
    }

    /* set fields */
    set->mode    = mode;
    set->size    = size;
    set->m       = m;
    set->reset   = gnn_output_default_reset;
    set->put     = put;
    set->destroy = gnn_output_default_destroy;

    /* install functions */
    if (reset != NULL)
        set->reset = reset;
    if (destroy != NULL)
        set->destroy = destroy;

    return 0;
}

/**
 * @brief Initializes a \ref gnn_output stream device.
 * @ingroup gnn_output_doc
 *
 * This function initializes a given stream vector writer, setting its
 * properties and installing its functions. Please refer to
 * \ref gnn_output_init for detailed documentation.
 *
 * @param  set   A pointer to a \ref gnn_output.
 * @param  reset   A pointer to the output's "reset" function.
 * @param  put     A pointer to the output's "put" function.
 * @param  destroy A pointer to the output's "destroy" function.
 * @return 0 if succeeded.
 */
int
gnn_output_stream_init (gnn_output *set,
                        gnn_output_reset_type   reset,
                        gnn_output_put_type     put,
                        gnn_output_destroy_type destroy)
{
    return gnn_output_init (set, gnnOutputStream, 0, 0, reset, put, destroy);
}

/**
 * @brief Initializes a \ref gnn_output random access device.
 * @ingroup gnn_output_doc
 *
 * This function initializes a given random access vector writer, setting its
 * properties and installing its functions. Please refer to
 * \ref gnn_output_init for detailed documentation.
 *
 * @param  set   A pointer to a \ref gnn_output.
 * @param  size  The number of samples that it can contain.
 * @param  m     The size of the output samples.
 * @param  reset   A pointer to the output's "reset" function.
 * @param  put     A pointer to the output's "put" function.
 * @param  destroy A pointer to the output's "destroy" function.
 * @return 0 if succeeded.
 */
int
gnn_output_random_access_init (gnn_output  *set,
                               size_t       size,
                               size_t       m,
                               gnn_output_reset_type   reset,
                               gnn_output_put_type     put,
                               gnn_output_destroy_type destroy)
{
    return gnn_output_init (set, gnnOutputRA, size, m, reset, put, destroy);
}

/**
 * @brief Destroy a \ref gnn_output.
 * @ingroup gnn_output_doc
 *
 * This function destroys the output reader.
 *
 * @param set A pointer to a \ref gnn_output.
 */
void
gnn_output_destroy (gnn_output *set)
{
    assert (set != NULL);

    set->destroy (set);
    free (set);
}

/**
 * @brief Reset a output set.
 * @ingroup gnn_output_doc
 *
 * This function resets the output handler.
 *
 * @param  set A pointer to a \ref gnn_output.
 * @return 0 if succeeded.
 */
int
gnn_output_reset (gnn_output *set)
{
    assert (set != NULL);

    set->reset (set);
}

/**
 * @brief Puts the k-th sample.
 * @ingroup gnn_output_doc
 *
 * This function writes the given vector at the k-th position of the output
 * device.
 *
 * @param  set    A pointer to a \ref gnn_input.
 * @param  k      The index of the sample to be retrieved.
 * @param  v      A pointer to the vector that should be outputted.
 * @return Returns 0 if succeeded.
 */
int
gnn_output_put (gnn_output *set, size_t k, const gsl_vector *v)
{
    assert (set != NULL);

    return set->put (set, k, v);
}

/**
 * @brief Gets the number of samples in the output.
 * @ingroup gnn_output_doc
 *
 * This function returns the output set's size. This number normally identifies
 * the number of samples that the output device can handle simultaneously.
 * It corresponds also to the maximum index that can be given in a call
 * at \ref gnn_output_put.
 *
 * @param  set A pointer to a \ref gnn_output.
 * @return Returns the size.
 */
size_t
gnn_output_get_size (gnn_output *set)
{
    assert (set != NULL);

    return set->size;
}

/**
 * @brief Gets the output sample size.
 * @ingroup gnn_output_doc
 *
 * This function returns the size of the output vectors that are written to
 * this output device.
 *
 * @param  set A pointer to a \ref gnn_output.
 * @return Returns the size.
 */
size_t
gnn_output_sample_get_size (gnn_output *set)
{
    assert (set != NULL);

    return set->m;
}

/**
 * @brief Check if stream device.
 * @ingroup gnn_output_doc
 *
 * This function returns 1 if the device is a stream device.
 *
 * @param  set A pointer to a \ref gnn_output.
 * @return Returns 1 if the output is a stream device or 0 if not.
 */
int
gnn_output_is_stream (gnn_output *set)
{
    assert (set != NULL);

    if (set->mode == gnnOutputStream)
        return 1;
    else
        return 0;
}

/**
 * @brief Check if random access device.
 * @ingroup gnn_output_doc
 *
 * This function returns 1 if the device is a random access output device.
 *
 * @param  set A pointer to a \ref gnn_output.
 * @return Returns 1 if the output is a RA device or 0 if not.
 */
int
gnn_output_is_random_access (gnn_output *set)
{
    assert (set != NULL);

    if (set->mode == gnnOutputRA)
        return 1;
    else
        return 0;
}

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