The archive size indicates a portion of the subpopulation that is
retained on every generation of the SPEA2 algorithm. The archive
preserves a sampling of the nondominated front.
From Zitzler et. al., "SPEA2: Improving the Strength Pareto
"Environmental selection: Besides the population, an archive is
contains a representation of the nondominated front among all
sidered so far. A member of the archive is only removed if i) a
solution has been
found that dominates it or ii) the maximum archive size is exceeded
and the por-
tion of the front where the archive member is located is overcrowded.
being copied to the archive is the only way how an individual can
eral generations in addition to pure reproduction which may occur by
This technique is incorporated in order not to lose certain portions
of the current
nondominated front due to random effects."
On Jul 7, 2009, at 7:36 AM, Paul Fisher wrote:
> I'd like to use the SPEA2 package, but don't understand what the
> purpose of the archive_size parameter is in the SPEA2Subpopulation
> Any advice appreciated.