gnn_cross_entropy.h Source File

00001 /***************************************************************************
00002  *  @file gnn_cross_entropy.h
00003  *  @brief Cross Entropy Error Criterion.
00004  *
00005  *  @date   : 25-08-03 23:20
00006  *  @author : Pedro Ortega C. <peortega@dcc.uchile.cl>
00007  *  Copyright  2003  Pedro Ortega C.
00008  ****************************************************************************/
00009 /*
00010  *  This program is free software; you can redistribute it and/or modify
00011  *  it under the terms of the GNU General Public License as published by
00012  *  the Free Software Foundation; either version 2 of the License, or
00013  *  (at your option) any later version.
00014  *
00015  *  This program is distributed in the hope that it will be useful,
00016  *  but WITHOUT ANY WARRANTY; without even the implied warranty of
00017  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
00018  *  GNU Library General Public License for more details.
00019  *
00020  *  You should have received a copy of the GNU General Public License
00021  *  along with this program; if not, write to the Free Software
00022  *  Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
00023  */
00024 
00025 #ifndef _GNN_CROSS_ENTROPY_H_
00026 #define _GNN_CROSS_ENTROPY_H_
00027 
00028 /******************************************/
00029 /* Include Files                          */
00030 /******************************************/
00031 
00032 #include "gnn_criterion.h"
00033 
00034 
00035 
00036 /******************************************/
00037 /* Macros and Definitions                 */
00038 /******************************************/
00039 
00040 /**
00041  * @brief Minimum value to be evaluated in a logarithm.
00042  * @ingroup gnn_cross_entropy_doc
00043  *
00044  * The evaluation of the cross entropy criterion has some tricky parts.
00045  * Whenever the natural logarithm of a very small quantity is to be taken,
00046  * then this value sets the limit.
00047  */
00048 #define GNN_CROSS_ENTROPY_EPS 0.0001
00049 
00050 
00051 
00052 /******************************************/
00053 /* Public Interface                       */
00054 /******************************************/
00055 
00056 gnn_criterion *
00057 gnn_cross_entropy_new (size_t size);
00058 
00059 
00060 #endif /* _GNN_CROSS_ENTROPY_H_ */
00061 
00062 
00063