  We present evidence that multigrid (MG) works for wave equations in
disordered systems, e.g. in the presence of gauge fields, no matter how strong
the disorder. We introduce a "neural computations" point of view into large
scale simulations: First, the system must learn how to do the simulations
efficiently, then do the simulation (fast). The method can also be used to
provide smooth interpolation kernels which are needed in multigrid Monte Carlo
updates.
