src/som.h

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/***************************************************************************
 *   Copyright (C) 2008/2009 by Matthias Ihrke                                  *
 *   mihrke@uni-goettingen.de                                              *
 *                                                                         *
 *   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 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.             *
 ***************************************************************************/

#ifndef SOM_H
# define SOM_H

#include "definitions.h"
#include "helper.h"
#include "distances.h"

#ifdef __cplusplus
extern "C" {
#endif
    /*-----------------------------------------------------------
     - Self-Organizing Maps (SOM)
     ---------------------------------------------------------*/

  struct som_struct;
  typedef double(*NeighbourhoodFunction)(int,int,struct som_struct*, int t);

  typedef double(*TimeDecayFunction)(int,int,int);

  typedef enum {
    ONED_LINEAR,
    TWOD_GRID,
    TWOD_HEXAGONAL,
    CUSTOM
  } SOMConnectivityType;

  typedef struct som_struct {
     double  **m; 
     int     dimension; 
     int     n; 
     VectorDistanceFunction distancefct; 
     void    *distancefct_parameters; 
     int     nruns; 
     int     initial_runs; 
     NeighbourhoodFunction neighbourhoodfct; 
     TimeDecayFunction     time_decay; 
     SOMConnectivityType connectivity_type; 
     double **connectivity; 
     gsl_rng_type *random_number_type; 
     gsl_rng *rng; 
     ProgressBarFunction progress; 
  } Som;

  Som* som_init( int dimension, int n, int nruns, SOMConnectivityType connectivity );
  void som_free( Som *s );
  void som_print( FILE *f, Som *s );

  void som_initialize_random( Som *s, double min, double max );
  void som_initialize_random_samples( Som *s, double **X, int dim, int nsamples );
  double** som_generate_connectivity_matrix( SOMConnectivityType type, double **m, int n );

  double som_neighbourhood_gaussian( int x, int bmu, struct som_struct *s, int t);

  double som_time_decay_linear( int t, int nruns, int initial_runs );

  void som_train_from_data( Som *s, double **X, int dim, int nsamples );

#ifdef __cplusplus
}
#endif

#endif /* SOM_H */