/*
* geqo_selection
* according to bias described by input parameters,
* first and second genes are selected from the pool
*/
void
geqo_selection(PlannerInfo *root, Chromosome *momma, Chromosome *daddy,
Pool *pool, double bias)
{
int first,
second;
first = linear_rand(root, pool->size, bias);
second = linear_rand(root, pool->size, bias);
/*
* Ensure we have selected different genes, except if pool size is only
* one, when we can't.
*
* This code has been observed to hang up in an infinite loop when the
* platform's implementation of erand48() is broken. We consider that a
* feature: it lets you know you'd better fix the random-number generator.
*/
if (pool->size > 1)
{
while (first == second)
second = linear_rand(root, pool->size, bias);
}
geqo_copy(root, momma, &pool->data[first], pool->string_length);
geqo_copy(root, daddy, &pool->data[second], pool->string_length);
}
/*
* geqo_selection
* according to bias described by input parameters,
* first and second genes are selected from the pool
*/
void
geqo_selection(PlannerInfo *root, Chromosome *momma, Chromosome *daddy,
Pool *pool, double bias)
{
int first,
second;
first = linear_rand(root, pool->size, bias);
second = linear_rand(root, pool->size, bias);
/*
* Ensure we have selected different genes, except if pool size is only
* one, when we can't.
*
* This code was observed to hang up in an infinite loop when the
* platform's implementation of erand48() was broken. We now always use
* our own version.
*/
if (pool->size > 1)
{
while (first == second)
second = linear_rand(root, pool->size, bias);
}
geqo_copy(root, momma, &pool->data[first], pool->string_length);
geqo_copy(root, daddy, &pool->data[second], pool->string_length);
}
/*
* geqo_selection
* according to bias described by input parameters,
* first and second genes are selected from the pool
*/
void
geqo_selection(Chromosome *momma, Chromosome *daddy, Pool *pool, double bias)
{
int first,
second;
first = linear(pool->size, bias);
second = linear(pool->size, bias);
if (pool->size > 1)
{
while (first == second)
second = linear(pool->size, bias);
}
geqo_copy(momma, &pool->data[first], pool->string_length);
geqo_copy(daddy, &pool->data[second], pool->string_length);
}
/* spread_chromo
* inserts a new chromosome into the pool, displacing worst gene in pool
* assumes best->worst = smallest->largest
*/
void
spread_chromo(planner_info_n *root, Chromosome *chromo, Pool *pool)
{
int top;
int mid;
int bot;
int i;
int index;
Chromosome swap_chromo;
Chromosome tmp_chromo;
/* new chromo is so bad we can't use it */
if (chromo->worth > pool->data[pool->size - 1].worth)
return;
/* do a binary search to find the index of the new chromo */
top = 0;
mid = pool->size / 2;
bot = pool->size - 1;
index = -1;
while (index == -1) {
/* these 4 cases find a new location */
if (chromo->worth <= pool->data[top].worth)
index = top;
else if (chromo->worth == pool->data[mid].worth)
index = mid;
else if (chromo->worth == pool->data[bot].worth)
index = bot;
else if (bot - top <= 1)
index = bot;
/*
* these 2 cases move the search indices since a new location has not
* yet been found.
*/
else if (chromo->worth < pool->data[mid].worth) {
bot = mid;
mid = top + ((bot - top) / 2);
} else {
/* (chromo->worth > pool->data[mid].worth) */
top = mid;
mid = top + ((bot - top) / 2);
}
} /* ... while */
/* now we have index for chromo */
/*
* move every gene from index on down one position to make room for chromo
*/
/*
* copy new gene into pool storage; always replace worst gene in pool
*/
geqo_copy(root, &pool->data[pool->size - 1], chromo, pool->string_length);
swap_chromo.string = pool->data[pool->size - 1].string;
swap_chromo.worth = pool->data[pool->size - 1].worth;
for (i = index; i < pool->size; i++) {
tmp_chromo.string = pool->data[i].string;
tmp_chromo.worth = pool->data[i].worth;
pool->data[i].string = swap_chromo.string;
pool->data[i].worth = swap_chromo.worth;
swap_chromo.string = tmp_chromo.string;
swap_chromo.worth = tmp_chromo.worth;
}
}
