statistics for GIS?

[ALOBO]

"""however, the return
trip is not trivial, or if it is, my abilities are less than trivial.
i use the binary-tree capabilities of S-Plus and need to reproduce
the tree structure in a language that GRASS understands, not the
S-Plus object stored and maintained in S-Plus for further tree
analyses and prediction. S-Plus will not handle data sets the size
of which i am using, so i go through the painful and tedious process
of reconstructing the final trees in r.mapcalc.  an interface between
S-Plus and GRASS would presumably eliminate this step."""

I'm a bit confused about your needs. Could you provide an example?
What I normaly do is to use Grass to generate data files according to
GIS (grass) rules. Then I Use Splus over those files and bring the 
results to grass again for display and further GIS processing. To
import/export to/from Splus I use simple functions that are based
on write and scan Splus commands. The most "sophisticated" (but still
very simple) is the function that I wrote to import binary (cell) 
grass files to Splus (and the equivalent to export it).

"""i currently
plan to switch to arc/info since i understand that it does talk to S-Plus,
or will in the near future."""

Could you detail what kind of "talk" they perform?

Agus