Abstract
Gene Expression Programming (GEP) is a new technique
of Genetic Programming (GP) that implements a linear
genotype representation. It uses fixed-length
chromosomes to represent expression trees of different
shapes and sizes, which results in unconstrained search
of the genome space while still ensuring validity of
the programs output. However, GEP has some difficulty
in discovering suitable function structures because the
genetic operators are more disruptive than traditional
tree-based GP. One possible remedy is to specifically
assist the algorithm in discovering useful numeric
constants. In this paper, the effectiveness of several
constant creation techniques for GEP has been
investigated through two symbolic regression benchmark
problems. Our experimental results show that constant
creation methods applied to the whole population for
selected generations perform better than methods that
are applied only to the best individuals. The proposed
tune-up process for the entire population can
significantly improve the average fitness of the best
solutions.
Users
Please
log in to take part in the discussion (add own reviews or comments).