[Carpet] question on grid structures and interpolation

[Yosef Zlochower]

Hi,

  I have a routine, which is scheduled in local mode, that interpolated GFs
at specific points. I wanted to set up the routine so that it would only
do the interpolation if the current component of the current level contains
the interpolation point. I tried to get the bounds of the current component
using the code

lx  = CCTK_ORIGIN_SPACE(0);
ux = lx + (cctk_gsh[0] -1)*CCTK_DELTA_SPACE(0);
etc.

My grid is set up so that I have n refinement levels about two separate 
locations
(using the CarpetRegrid2 thorn). I found, however, that the range 
(lx,ux) seems to
contain both centers for all refinement levels. Does this mean that I am 
actually
using much bigger grids than I thought, or does the above calculation 
only give
me results for a `virtual' grid which contains all components of the 
real grids at
a particular refinement level?

In addition, would be the result if I attempt to interpolate a data 
point from another
component of the same refinement level?

Yosef