The quick answer is "nope" :-) Part of the reason is that we don't want to embed the assumption that the hierarchy has the same depth everywhere in code, and methods like that are hard to use without that assumption. The original idea had been that one would extract layers from the hierarchy by various criteria, such as radius. That is, ask for - give me the finest level representation - give me a representation where the particles all have radius close to 15A etc The atom::Selection class gives that sort of capability (by setting the radius for the selection).

On Mon, May 21, 2012 at 1:43 PM, Charles Greenberg cgreen@salilab.orgwrote:

> Hey Daniel. Question for you. Kale is doing some very cool domino > experiments, using multiple levels of beads (coarse to fine) with a set of > distance restraints at each level. Currently he's using a simple dictionary > to establish connections between the levels, but he suggested it would be > cool to use the IMP hierarchy format. It's pretty clear how to make a > general hierarchy of particles, and to get children and parents, but is > there code to do simple queries like "How many levels are there?" and "Get > me all particles at level X"? Thanks! > > --Charles