abstract = "We present N-gram GP, an estimation of distribution
algorithm for the evolution of linear computer
programs. The algorithm learns and samples a joint
probability distribution of triplets of instructions
(or 3-grams) at the same time as it is learning and
sampling a program length distribution. We have tested
N-gram GP on symbolic regressions problems where the
target function is a polynomial of up to degree 12 and
lawn-mower problems with lawn sizes of up to 12x12.
Results show that the algorithm is effective and scales
better on these problems than either linear GP or
simple stochastic hill-climbing.",