On Feb 17, 2009, at 1:23 AM, Daniel Russel wrote:
> It came up in the context of rigid bodies that certain optimizers > (namely CG) like to have all their parameters vary over a similar > scale. As a result, it can be important to rescale non-xyz > attributes. One way of doing this would be to add a method to Model: > FloatPair get_range(FloatKey) which returns the current range of > values for a particular FloatKey. Then CG could use that to rescale > all its values internally. something like that would be useful indeed. the typical changes of the values would be of importance for optimizers - the absolute values are not really important. thus, this function would somehow need to accumulate knowledge on the magnitude of changes for the variables throughout optimization.
cheers
frido > > > If it is useful to be able to override the range, we could also add > set_range which allows you to set the expected range (perhaps even > allowed range) for a given attribute type. > > Both of these would be relatively easy to implement on the Model > side. The CG code is a bit hairy, so tweaking that could take more > work (and is probably best done by adding another set of methods to > access the values in the Optimizer base class). > _______________________________________________ > IMP-dev mailing list > IMP-dev@salilab.org > https://salilab.org/mailman/listinfo/imp-dev >
--
Friedrich Foerster Max-Planck Institut fuer Biochemie Am Klopferspitz 18 D-82152 Martinsried
Tel: +49 89 8578 2651 Fax: +49 89 8578 2641
foerster@biochem.mpg.de
www.tomotronic.org