Hi, all--

Can I hand a cut_region to a projection? 

I want to make a bunch of projections based on parameters, and don't want to have to instantiate 47 different fields.  I'm hoping something like

region = pf.h.all_data().cut_region('grid["Density"] > 0.1 and grid["Density"] < 0.2')
proj = pf.h.proj(0,"Density",region=cut_region)

or something like that.  Is that possible?  I'm poking around the help and source, but no method immediately popped out at me.