# Adding Local Edge Mobility to Graph Evolution

### Daniel Ashlock and Meghan Timmins

Submitted to CEC 2016

This study extends an earlier generative representation for the
evolution of graphs to include a local reconfiguration operator and a
null operator. The local reconfiguration operator is shown to be more
effective in evolving graphs with a particular geometric character
(eccentricity sequence). The null operator permits evolution to select
the number of active commands used, avoiding a problem with needing to
tune a "gene length" parameter. The representation is parametrized by
the probability of each command appearing in initial populations and
during mutation. A parameter study leads to a number of rules of thumb
for using the new representation and it is found that the number of
failures to find a solution, in 3000 attempts, varies from 17 in 3000
as the parameters are changed. The representation is tested on 100
instances of the eccentricity sequence matching problem. Use of the
null operator has the beneficial side effect of reducing observed
variation in problem difficulty.