thanks. i will employ ben's solution for the time being. if it my method is successful and of use for others i will bug you to find a more elegant and faster solution.

best

frido

On Jun 26, 2008, at 4:30 PM, Daniel Russel wrote:

> > On Jun 25, 2008, at 5:02 PM, Ben Webb wrote: > >> Friedrich Foerster wrote: >>> i spread imp throughout the world. even in exotic bavaria imp is >>> functional now. >>> here, i am trying ever more challenging things: i am using >>> restraints >>> from different sources and want to weight these terms differently. >>> for >>> that purpose, i want to employ a common strategy in x-ray: the >>> different >>> restraints are weighted according to the inverse magnitude of the >>> corresponding derivatives. >>> Do you know a way how to get the derivatives of a particle with >>> respect >>> to a specific restraint set in IMP. Particle.get_derivative uses the >>> full scoring function as i understand it... >> >> It's not something that's immediately possible, as I see it, in IMP >> currently. But I suppose you could go through every *other* restraint >> and call set_is_active(false). Otherwise, if what you want to do is >> precisely that - weight the restraints by the derivatives - then >> perhaps >> we could add extra functionality to the DerivativeAccumulator to >> allow >> for that. > To expand a little, it wouldn't be too hard to have the DA compute > some metric on the derivatives it has been used to accumulate and > then have a restraint set which looks at this value and uses it to > compute its weight. The DA doesn't have any way of differentiating > between different attributes though, in case that matters.