Functional links transform the input pattern space to a new pattern space. As functional links one can use polynomials, or more general functions. Both can be found using evolutionary computation. Polynomial functional links are found by evolving a coding of the powers of the polynomial. For symbolic functions we can use genetic programming.
Genetic programming finds the symbolic functions that are to be applied to the inputs.
We compare the workings of the latter two methods on two artificial datasets, and on a real-world medical image dataset.