mutate.c

Genetic Programing of music

/*  lil-gp Genetic Programming System, version 1.0, 11 July 1995
 *  Copyright (C) 1995  Michigan State University
 * 
 *  This program is free software; you can redistribute it and/or modify
 *  it under the terms of version 2 of the GNU General Public License as
 *  published by the Free Software Foundation.
 * 
 *  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., 675 Mass Ave, Cambridge, MA 02139, USA.
 *  
 *  Douglas Zongker       ([e-mail])
 *  Dr. Bill Punch        ([e-mail])
 *
 *  Computer Science Department
 *  A-714 Wells Hall
 *  Michigan State University
 *  East Lansing, Michigan  48824
 *  USA
 *  
 */

#include <lilgp.h>

typedef struct
{
     int keep_trying;
     double internal;
     double external;
     double *tree;
     double treetotal;
     char *sname;
     sel_context *sc;
     int method;
     int mindepth, maxdepth;
} mutate_data;

/* operator_mutate_init()
 *
 * initialize a breedphase record for mutation.  much of this is cut and
 * paste from the crossover operator; see that for (a few) more comments.
 */

int operator_mutate_init ( char *options, breedphase *bp )
{
     int errors = 0;
     mutate_data *md;
     int i, j, k, m;
     double r;
     char **argv, **targv;
     int internalset = 0, externalset = 0;
     char *cp;

     md = (mutate_data *)MALLOC ( sizeof ( mutate_data ) );

     /* fill in the breedphase record. */
     bp->operator = OPERATOR_MUTATE;
     bp->data = (void *)md;
     bp->operator_free = operator_mutate_free;
     bp->operator_start = operator_mutate_start;
     bp->operator_end = operator_mutate_end;
     bp->operator_operate = operator_mutate;

     /* default values for the mutation-specific data structure. */
     md->keep_trying = 0;
     md->internal = 0.9;
     md->external = 0.1;
     md->tree = (double *)MALLOC ( tree_count * sizeof ( double ) );
     for ( j = 0; j < tree_count; ++j )
          md->tree[j] = 0.0;
     md->treetotal = 0.0;
     md->sname = NULL;
     md->method = GENERATE_HALF_AND_HALF;
     md->mindepth = -1;
     md->maxdepth = -1;
     
     j = parse_o_rama ( options, &argv );

     for ( i = 0; i < j; ++i )
     {
          if ( strcmp ( "keep_trying", argv[i] ) == 0 )
          {
               md->keep_trying = translate_binary ( argv[++i] );
               if ( md->keep_trying == -1 )
               {
                    ++errors;
                    error ( E_ERROR, "mutation: \"%s\" is not a valid setting for \"keep_trying\".",
                           argv[i] );
               }
          }
          else if ( strcmp ( "internal", argv[i] ) == 0 )
          {
               internalset = 1;
               md->internal = strtod ( argv[++i], NULL );
               if ( md->internal < 0.0 )
               {
                    ++errors;
                    error ( E_ERROR, "mutation: \"internal\" must be nonnegative." );
               }
          }
          else if ( strcmp ( "external", argv[i] ) == 0 )
          {
               externalset = 1;
               md->external = strtod ( argv[++i], NULL );
               if ( md->external < 0.0 )
               {
                    ++errors;
                    error ( E_ERROR, "mutation: \"external\" must be nonnegative." );
               }
          }
          else if ( strcmp ( "select", argv[i] ) == 0 )
          {
               if ( !exists_select_method ( argv[++i] ) )
               {
                    ++errors;
                    error ( E_ERROR, "mutation: \"%s\" is not a known selection method.",
                           argv[i] );
               }
               FREE ( md->sname );
               md->sname = (char *)MALLOC ( (strlen(argv[i])+1) * sizeof ( char ) );
               strcpy ( md->sname, argv[i] );
          }
          else if ( strcmp ( "method", argv[i] ) == 0 )
          {
               ++i;
               if ( strcmp ( argv[i], "half_and_half" ) == 0 )
                    md->method = GENERATE_HALF_AND_HALF;
               else if ( strcmp ( argv[i], "grow" ) == 0 )
                    md->method = GENERATE_GROW;
               else if ( strcmp ( argv[i], "full" ) == 0 )
                    md->method = GENERATE_FULL;
               else
               {
                    ++errors;
                    error ( E_ERROR, "mutation: \"%s\" is not a known generation method.",
                           argv[i] );
               }
          }
          else if ( strcmp ( "depth", argv[i] ) == 0 )
          {
               md->mindepth = strtol ( argv[++i], &cp, 10 );
               if ( *cp == 0 )
                    md->maxdepth = md->mindepth;
               else if ( *cp == '-' )
               {
                    md->maxdepth = strtol ( cp+1, &cp, 10 );
                    if ( *cp )
                    {
                         ++errors;
                         error ( E_ERROR, "mutation: malformed depth string \"%s\".",
                                argv[i] );
                    }
               }
               else
               {
                    ++errors;
                    error ( E_ERROR, "mutation: malformed depth string \"%s\".",
                           argv[i] );
               }
          }
          else if ( strcmp ( "tree", argv[i] ) == 0 )
          {
               k = parse_o_rama ( argv[++i], &targv );
               if ( k != tree_count )
               {
                    ++errors;
                    error ( E_ERROR, "mutation: wrong number of tree fields: \"%s\".",
                           argv[i] );
               }
               else
               {
                    for ( m = 0; m < k; ++m )
                    {
                         md->tree[m] = strtod ( targv[m], &cp );
                         if ( *cp )
                         {
                              ++errors;
                              error ( E_ERROR, "mutation: \"%s\" is not a number.",
                                     targv[m] );
                         }
                    }
               }
               
               free_o_rama ( k, &targv );
          }
          else if ( strncmp ( "tree", argv[i], 4 ) == 0 )
          {
               k = strtol ( argv[i]+4, &cp, 10 );
               if ( *cp )
               {
                    ++errors;
                    error ( E_ERROR, "mutation: unknown option \"%s\".",
                           argv[i] );
               }
               if ( k < 0 || k >= tree_count )
               {
                    ++errors;
                    error ( E_ERROR, "mutation: \"%s\" is out of range.",
                           argv[i] );
               }
               else
               {
                    md->tree[k] = strtod ( argv[++i], &cp );
                    if ( *cp )
                    {
                         ++errors;
                         error ( E_ERROR, "mutation: \"%s\" is not a number.",
                                argv[i] );
                    }
               }
          }
          else
          {
               ++errors;
               error ( E_ERROR, "mutation: unknown option \"%s\".",
                      argv[i] );
          }
     }
     
     free_o_rama ( j, &argv );
     
     if ( internalset && !externalset )
          md->external = 0.0;
     else if ( !internalset && externalset )
          md->internal = 0.0;
     
     if ( md->sname == NULL )
     {
          ++errors;
          error ( E_ERROR, "mutation: no selection method specified." );
     }

     if ( md->mindepth == -1 && md->maxdepth == -1 )
     {
          md->mindepth = 0;
          md->maxdepth = 4;
     }
     
     if ( md->mindepth < 0 || md->maxdepth < 0 ||
         md->maxdepth < md->mindepth )
     {
          ++errors;
          error ( E_ERROR, "mutation: bad depth range.\n" );
     }
     
     for ( j = 0; j < tree_count; ++j )
          md->treetotal += md->tree[j];
     if ( md->treetotal == 0.0 )