Abstract
The principle of minimum description length suggests looking for the simplest network that works well on the training examples, where simplicity is measured by network description size based on a reasonable programming language for encoding networks. Previous work used an assembler-like universal network encoding language (NEL) and Speed Prior based search (related to Levin's Universal Search) to quickly find low-complexity nets with excellent generalization performance, Here we define a more natural and often more practical NEL whose instructions are frequency domain coefficients. Frequency coefficients may get encoded by few bits, hence huge weight matrices may just be low-complexity superpositions of patterns computed by programs with few elementary instructions. On various benchmarks this weight matrix encoding greatly accelerates the search. The scheme was tested on pole-balancing, long-term dependency T-maze, and ball throwing. Some of the solutions turn out to be unexpectedly simple as they are computable by fairly short bit strings.