realcross2.h

多目标遗传算法的源代码

/*This is the file used for crossover for Real Coded GA*/

void realcross(population *new_pop_ptr,population *mate_pop_ptr);

void realcross(population *new_pop_ptr,population *mate_pop_ptr)
{
int i,j,y,n,r;
float rnd,par1,par2,chld1,chld2,betaq,beta,alpha;
float y1,y2,yu,yl,expp;

y=0; n=0;
for(i = 0; i < popsize/2; i++)
{
rnd = randomperc();

/*Check Whether the cross-over to be performed*/
if(rnd <= pcross)
{

/*Loop over no of variables*/
for(j = 0;j < nvar;j++)
{
/*Selected Two Parents*/
par1 = mate_pop_ptr->ind[y].xreal[j];
par2 = mate_pop_ptr->ind[y+1].xreal[j];

yl = lim_r[j][0];
yu = lim_r[j][1];

rnd = randomperc();

/* Check whether variable is selected or not*/
if(rnd <= 0.5)
{
/*Variable selected*/
ncross++;

if(fabs(par1 - par2) > 0.000001) // changed by Deb (31/10/01)
{
if(par2 > par1)
{
y2 = par2;
y1 = par1;
}
else
{
y2 = par1;
y1 = par2;
}

/*Find beta value*/
if((y1 - yl) > (yu - y2))
{
beta = 1 + (2*(yu - y2)/(y2 - y1));
//printf("beta = >f\n",beta);
}
else
{
beta = 1 + (2*(y1-yl)/(y2-y1));
//printf("beta = >f\n",beta);
}

/*Find alpha*/
expp = di + 1.0;

beta = 1.0/beta;

alpha = 2.0 - pow(beta,expp);

if (alpha < 0.0)
{
printf("ERRRROR >f >d >d >f >f\n",alpha,y,n,par1,par2);
exit(-1);
}

rnd = randomperc();

if (rnd <= 1.0/alpha)
{
alpha = alpha*rnd;
expp = 1.0/(di+1.0);
betaq = pow(alpha,expp);
}
else
{
alpha = alpha*rnd;
alpha = 1.0/(2.0-alpha);
expp = 1.0/(di+1.0);
if (alpha < 0.0)
{
printf("ERRRORRR \n");
exit(-1);
}
betaq = pow(alpha,expp);
}

/*Generating two children*/
chld1 = 0.5*((y1+y2) - betaq*(y2-y1));
chld2 = 0.5*((y1+y2) + betaq*(y2-y1));

}
else
{

betaq = 1.0;
y1 = par1; y2 = par2;

/*Generation two children*/
chld1 = 0.5*((y1+y2) - betaq*(y2-y1));
chld2 = 0.5*((y1+y2) + betaq*(y2-y1));

}
// added by deb (31/10/01)
if (chld1 < yl) chld1 = yl;
if (chld1 > yu) chld1 = yu;
if (chld2 < yl) chld2 = yl;
if (chld2 > yu) chld2 = yu;
}
else
{

/*Copying the children to parents*/
chld1 = par1;
chld2 = par2;
}
new_pop_ptr->ind[n].xreal[j] = chld1;
new_pop_ptr->ind[n+1].xreal[j] = chld2;
}
}
else
{
for(j = 0;j < nvar;j++)
{
par1 = mate_pop_ptr->ind[y].xreal[j];
par2 = mate_pop_ptr->ind[y+1].xreal[j];
chld1 = par1;
chld2 = par2;
new_pop_ptr->ind[n].xreal[j] = chld1;
new_pop_ptr->ind[n+1].xreal[j] = chld2;
}
}
n = n+2; y=y+2;
}
return;
}