rselect.c

来自「遗传算法的简单程序」· C语言 代码 · 共 34 行

//选择 
/*-----------------------------------------*/ 
/* rselect.c:  roulette wheel selection.   */ 
/*-----------------------------------------*/ 
#include "external.h" 
select_memory() 
{ 
} 
select_free() 
{ 
} 
preselect() 
{ 
    int j; 
    sumfitness = 0; 
    for(j = 0; j < popsize; j++) sumfitness += oldpop[j].fitness; 
}
 
int select() /* roulette-wheel selection 轮盘赌选择*/ 
{ 
    extern float randomperc(); 
    float sum, pick; 
    int i; 
    pick = randomperc(); 
    sum = 0; 
    if(sumfitness != 0) 
    { 
        for(i = 0; (sum < pick) && (i < popsize); i++) 
            sum += oldpop[i].fitness/sumfitness;   
    } 
    else 
        i = rnd(1,popsize); 
    return(i-1); 
}