I think the three alternatives for weights are
1) Hide it in the restraint class. To make this clean, we should hide
the the ModelData* and mirror its functions in the Restraint base class
(strictly speaking we only need to mirror add_to_deriv, but for
symmetry, we should do all if we do one). For the return value, I would
suggest adding a function weighted_eval which is called by the Model or
RestraintSet instead of eval and calls eval internally. Then, anyone who
wants to override that directly will know they need to deal with the
weights themselves. Note that this proposal breaks if we move to a
"Particles as Objects" framework since adding to the deriv involves an
arbitrary function call.
I like this option, because I think it a very bad idea to rely on every
restraint to do the scaling itself. But I don't think it'll work for
restraints which contain other restraints - for example I may want a
restraint set which contains a bunch of other restraints, and would then
expect each restraint to be scaled twice - once by its own scale factor
and once by the set's. It seems like option (2) would be able to handle
this more easily - either that or we use option (1) together with
something like the DerivativeAccumulator that Keren proposed. Why don't
you like option 2?
Ben
--
http://salilab.org/~ben/
"It is a capital mistake to theorize before one has data."
- Sir Arthur Conan Doyle