/*SGPC: Simple Genetic Programming in C(c) 1993 by Walter Alden Tackett and Aviram Carmi  This code and documentation is copyrighted and is not in the public domain. All rights reserved.   - This notice may not be removed or altered.  - You may not try to make money by distributing the package or by using the   process that the code creates.  - You may not distribute modified versions without clearly documenting your   changes and notifying the principal author.  - The origin of this software must not be misrepresented, either by   explicit claim or by omission.  Since few users ever read sources,   credits must appear in the documentation.  - Altered versions must be plainly marked as such, and must not be   misrepresented as being the original software.  Since few users ever read   sources, credits must appear in the documentation.  - The authors are not responsible for the consequences of use of this    software, no matter how awful, even if they arise from flaws in it. If you make changes to the code, or have suggestions for changes,let us know!  (gpc@ipld01.hac.com)*/#ifndef lintstatic char selection_c_rcsid[]="$Id: selection.c,v 2.7 1993/05/29 22:59:21 gpc-avc Exp gpc-avc $";#endif/* * * $Log: selection.c,v $ * Revision 2.7  1993/05/29  22:59:21  gpc-avc * use M_PI from math.h instead of PI from gpc.h * * Revision 2.6  1993/04/22  07:39:12  gpc-avc * Removed old log messages * * Revision 2.5  1993/04/14  04:50:16  gpc-avc * just a change of the revision number * * */#include <stdio.h>#include <malloc.h>#include <errno.h>#include <math.h>#include "gpc.h"#ifdef ANSI_FUNCtree *find_tree(  pop_struct 	*pop,  int 		p,  int 		demes,  int 		nrows,  int 		ncols,  int		*worst,  int		*best  )#elsetree *find_tree(pop,p,demes,nrows,ncols,worst,best)  pop_struct	*pop;  int		p;  int 		demes;  int 		nrows;  int 		ncols;  int		*worst;  int		*best;#endif{  if (demes) {    return find_tree_using_demes(pop,p,nrows,ncols,worst,best);  } else {    switch (pop[p].selection_method) {    case TOURNAMENT:      return find_tree_using_tournament(pop,p,worst,best);    case OVERSELECT:      return 	find_tree_using_fitnessprop(pop,p,random_float_with_overselect(pop,p));    case FITNESSPROP:      return find_tree_using_fitnessprop(pop,p,random_float(1.0));    default:      fprintf(stderr,"Invalid selection method %d\n",pop[p].selection_method);      return (NULL);    }  }}#ifdef ANSI_FUNCtree *find_tree_using_demes(  pop_struct 	*pop,  int 		p,  int 		nrows,  int 		ncols,  int		*worst,  int		*best  )#elsetree *find_tree_using_demes(pop,p,nrows,ncols,worst,best)  pop_struct	*pop;  int		p;  int 		nrows;  int 		ncols;  int		*worst;  int		*best;#endif{  int   i,row,col;  int	best_index, best_i, worst_index;  /* Select tournament_K individuals */  for (i = 0; i < pop[p].tournament_K; i++) {    pop[p].tournament_index[i] =      cannonical_select(pop,p,nrows,ncols);#if DBDEMES == 1    printf(" %d (LID=%d, SF=%f)\n", i, pop[p].tournament_index[i],	   POP[p].standardized_fitness[pop[p].tournament_index[i]]);#endif  }  /* Find fitest individual */  best_index = worst_index = pop[p].tournament_index[best_i=0];  for (i = 1; i < pop[p].tournament_K; i++) {    if (POP[p].standardized_fitness[pop[p].tournament_index[i]] <	POP[p].standardized_fitness[best_index]) {      best_index = pop[p].tournament_index[i];      best_i = i;    }    if (POP[p].standardized_fitness[pop[p].tournament_index[i]] >=	POP[p].standardized_fitness[worst_index]) {      worst_index = pop[p].tournament_index[i];    }  }#if DBDEMES == 1  printf(" %d WON (linear id=%d)\n", best_i, best_index);#endif  *best = best_index;  *worst = worst_index;  return POP[p].population[best_index];}#ifdef ANSI_FUNCint cannonical_select (  pop_struct 	*pop,  int 		p,  int 		nrows,  int 		ncols  )#elseint cannonical_select(pop,p,nrows,ncols)  pop_struct	*pop;  int		p;  int 		nrows;  int 		ncols;#endif{  float		azimuth, range, x, y;  int		row,col,individual_id;  azimuth = random_float(2.0*M_PI);  range = gaussian_noise(0.0, pop[p].deme_search_radius_sigma);  x = (0.5+(float)(pop[p].my_col)) + range * (float) cos((double)azimuth);  y = (0.5+(float)(pop[p].my_row)) + range * (float) sin((double)azimuth);  if (x<0.0) x+= (float) ncols;  if (y<0.0) y+= (float) nrows;  col = ((int) x)%ncols;  row = ((int) y)%nrows;  individual_id = random_int(pop[p].population_size);#if DBDEMES == 1  printf("select id %d from row %d col %d for tournament slot",	 individual_id, row, col);#endif  return ((row*ncols) + col)*pop[p].population_size + individual_id;}#ifdef ANSI_FUNCfloat random_float_with_overselect(  pop_struct 	*pop,  int 		p  )#elsefloat random_float_with_overselect(pop,p)  pop_struct	*pop;  int		p;#endif{  float	boundary;  if (pop[p].population_size < 1000) {    fprintf(stderr,"population size %d is too small for overselection\n",	    pop[p].population_size);    exit(-1);  }  boundary = 320.0 / (float) (pop[p].population_size);  if (random_float(1.0) < 0.8) {    return random_float(1.0);  } else {    return (boundary + random_float(1.0-boundary));  }}#ifdef ANSI_FUNCtree *find_tree_using_tournament_2(  pop_struct	*pop,  int 		p  )#elsetree *find_tree_using_tournament_2(pop,p)  pop_struct 	*pop;  int		p;#endif{  int	index1, index2;  index1 = random_int(pop[p].population_size);  index2 = random_int(pop[p].population_size);  if (pop[p].standardized_fitness[index1] <      pop[p].standardized_fitness[index2])    return pop[p].population[index1];  else    return pop[p].population[index2];}#ifdef ANSI_FUNCtree *find_tree_using_tournament(  pop_struct 	*pop,  int 		p,  int		*worst,  int		*best  )#elsetree *find_tree_using_tournament(pop,p,worst,best)  pop_struct	*pop;  int		p;  int		*worst;  int		*best;#endif{  int   i;  int	best_fitness_index;  int	worst_fitness_index;  /* Select tournament_K individuals */  for (i = 0; i < pop[p].tournament_K; i++) {    pop[p].tournament_index[i] = random_int(pop[p].population_size);  }  /* Find fitest individual */  best_fitness_index = worst_fitness_index = pop[p].tournament_index[0];  for (i = 1; i < pop[p].tournament_K; i++) {    if (pop[p].standardized_fitness[pop[p].tournament_index[i]] <	pop[p].standardized_fitness[best_fitness_index]) {      best_fitness_index = pop[p].tournament_index[i];    }    if (pop[p].standardized_fitness[pop[p].tournament_index[i]] >=	pop[p].standardized_fitness[worst_fitness_index]) {      worst_fitness_index = pop[p].tournament_index[i];    }  }  *best = best_fitness_index;  *worst = worst_fitness_index;  return pop[p].population[best_fitness_index];}#ifdef ANSI_FUNCtree *find_tree_using_fitnessprop(  pop_struct 	*pop,  int 		p,  float 	thresh  )#elsetree *find_tree_using_fitnessprop(pop, p, thresh)  pop_struct	*pop;  int		p;  float		thresh;#endif{  int	i;  float	sum;  int	worst_index;  for (i=0, sum=0.0;       ((i<pop[p].population_size) && (sum < thresh));       sum += pop[p].normalized_fitness[pop[p].fitness_sort_index[i]], i++);  return pop[p].population[pop[p].fitness_sort_index[i-1]];}