statistics for GIS?

[Kelly Elder]

>>"""It would not be hard to imagine using much of the functionality of
>>S-Plus, from classification and regression trees to data visualization.
>>This would be a significant addition to the usefulness of GRASS."""
 
>There is no reason to do not use Splus for the statistical analysis
>of data coming from Grass. I do it a lot, I would say most of the time.
>It requires writing few and simple Splus functions.

i missed the original thread, but the above comments caught my eye.
i currently use S-Plus and GRASS daily.  i dump data from grass
into S-Plus, a trivial matter as Agus said.  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 currently
plan to switch to arc/info since i understand that it does talk to S-Plus,
or will in the near future.  i would rather stick with grass.

venables and ripley's new book on S-Plus is outstanding and includes
even more spatial statistics that are a gis dream.  they 
supplement mccauley's previous contributions, and are likely to
get more use and support given mccauley's overloaded work schedule.
at this point i feel S-Plus is SO valuable that it makes more sense
to switch gis's than mathematical packages.

if you read between the lines here, my programing abilities a poor,
and someone else could surely write a routine to transfer the tree
objects into GRASS.  has anybody out there done this?  the bigger
picture and the more pertinent question (that i probably missed in
the original message) is whether an interface is planned that would
allow use of all of the current S-Plus pearls in GRASS?

kelly

kelly at icess.ucsb.edu