realmut.h

epsMOEA

/* This is the module used to formulate the mutation routine*/

void real_mutate (individual * new_pop_ptr);

void
real_mutate (individual * new_pop_ptr)
{
  int i, j, r;
  float rnd, delta, indi, *ptr, *ptr1, deltaq;
  float y, yl, yu, val, xy;


  for (i = 0; i < N_of_x; i++)
    {
      rnd = randomperc ();

      /*For each variable find whether to do mutation or not */
      if (rnd <= p_mutation_real)
	{
	  y = new_pop_ptr->xreal[i];
	  yl = infimumx[i];
	  yu = supremumx[i];

	  if (y > yl)
	    {
	      /*Calculate delta */

	      if ((y - yl) < (yu - y))
		delta = (y - yl) / (yu - yl);
	      else
		delta = (yu - y) / (yu - yl);

	      rnd = randomperc ();

	      indi = 1.0 / (n_distribution_m + 1.0);

	      if (rnd <= 0.5)
		{
		  xy = 1.0 - delta;
		  val =
		    2 * rnd + (1 -
			       2 * rnd) * (pow (xy, (n_distribution_m + 1)));
		  deltaq = pow (val, indi) - 1.0;
		}
	      else
		{
		  xy = 1.0 - delta;
		  val =
		    2.0 * (1.0 - rnd) + 2.0 * (rnd -
					       0.5) * (pow (xy,
							    (n_distribution_m
							     + 1)));
		  deltaq = 1.0 - (pow (val, indi));
		}

	      /*Change the value for the parent */
	      //  *ptr  = *ptr + deltaq*(yu-yl);
	      // Added by Deb (31/10/01)
	      y = y + deltaq * (yu - yl);
	      if (y < yl)
		y = yl;
	      if (y > yu)
		y = yu;
	      new_pop_ptr->xreal[i] = y;
	    }
	  else			// y == yl
	    {
	      xy = randomperc ();
	      new_pop_ptr->xreal[i] = xy * (yu - yl) + yl;
	    }
	}
      //  ptr++;
    }

  return;
}