Problematic MultiField methods
Currently, MultiField has methods like s_sum, clip, and many transcendental functions. I'm wondering whether they make any sense: what's the point of computing the sum over all values in several fields ... or computing the sine of all field entries?
We currently use MultiField's norm property in minimization, but given that the components of the MultiField may have vastly different scales, is this actually a clever thing to do? This basically means that we stop minimizing once the field component with the largest values has converged ... not necessarily what we want.