/*==============================================         file : generate.c    purpose : new population generation developed : 1991     author : Kalyanmoy Deb================================================*/#include "mga.ext"long change_popsize()/*  find out popsize  */{	long size;	size = popsize;	if ((gen >= init_select_gen) && (gen <= cutpop_gen))	{		if ((gen == cutpop_gen) && (size > juxtpopsize))			size = juxtpopsize;		else if (gen <= cut_every_other_gen)		/* cut at every other generation */		{			if (cutpopflag == 1)			{				size = popsize / 2;				cutpopflag = 0;			}			else 				cutpopflag = 1;		}		else  /* cut at every generation */			size = popsize / 2;	}	return(size);}void primordial()/*  primordial phase  */{	int pos,count;	char msg[PAGEWIDTH];	long newpopsize;	TRACE("   Primordial entered");	/*  check whether population size needs to be changed   */	newpopsize = change_popsize();	/* shuffle the population */	pick = 0;	shuffle_pop();	count = 0;	/*  create a new population  */	while (count < newpopsize) {		/*  select an individual  */		pos = select_pop();		/* copy it in the new population  */		copy_chrom(oldpop[pos],&(newpop[count]));		count++;	}	popsize = newpopsize;	reallocate_memory(popsize);	TRACE("   Primordial exited\n");}void juxtapositional()/*  juxtapositional phase  */{	int pos1, pos2, count;	register int i;	struct INDIVIDUAL mate1, mate2;	TRACE("   Juxtapositional entered");		/* shuffle the population */	pick = 0;	shuffle_pop();	count = 0;	/* free memory allocated for new population */	freenewpop();	/*  create new population */	do {		/*  generate mate1 and mate2  */		storepop(&mate1,1);		/*  select two individuals for mating  */		pos1 = select_pop();		copy_chrom(oldpop[pos1],&mate1);		storepop(&mate2,1);		pos2 = select_pop();		copy_chrom(oldpop[pos2],&mate2);		/* cut and splice two individuals */		cut_and_splice(mate1,mate2);		/* put children individuals in new population  */		while (count < popsize && ! isempty(newchrom_stack)) {			if (pop_stack(&newchrom_stack,&(newpop[count])))			{				/*  perform mutation  */				mutation(&(newpop[count]));				/*  find out raw chrom  */				fill_chrom(&(newpop[count]));				/*  evaluate objective function value  */				newpop[count].fitness = 					objfunc(newpop[count].fullchrom);				count++;			}		}	}    while (count < popsize);	TRACE("   Juxtapositional exited\n");}void generate()/*   messy GA operation   */{	struct INDIVIDUAL *tempop;	printf("\nera = %d, generation = %d\n\n",era,gen);	TRACE("Generate entered");	if (gen <= prim_gen)		primordial();	else		juxtapositional();	statistics(newpop);	reportpop(newpop); 	/* copy newpop to oldpop */	tempop = oldpop;	oldpop = newpop;	newpop = tempop;	TRACE("Generate exited");}