abstract = "We employ a variant of Differential Evolution (DE) for
co-evolution of real coefficients in Genetic
Programming (GP). This GP+DE method is applied to 30
randomly generated symbolic regression problems of
varying difficulty. Expressions were evolved on
sparsely sampled points, but were evaluated for
accuracy using densely sampled points over much wider
ranges of inputs. The GP+DE had successful runs on 25
of 30 problems, whereas GP using Ephemeral Random
Constants succeeded on only 6 and the multi-objective
GP Eureqa on only 18. Although nesting DE slows down
each GP generation significantly, successful GP+DE runs
required many fewer GP generations than the other
methods and, in nearly all cases, the number of nodes
in the best evolved trees were smaller in GP+DE than
with the other GP methods.",
notes = "Also known as \cite{2330891} Distributed at
GECCO-2012.