* textual attributes for integer grids by an anonymous hash with pairs
1 => 'water' etc, this should be implemented with the database

* operations: distance_to(cell or region), direction_to(cell or
region), these are now implemented in some way

* operations: 
	a = pick(b,c,d,...) a gets the nonzero values of b, then nonzero values of c, etc.
  	a = comb(b,c,d,...) ?
	a = count(b,c,d,...) number of nonzeros
	a = majority(b,c,d,...)
	a = minority(b,c,d,...)
	a = average(b,c,d,...)
	a = variance(b,c,d,...)
	a = nearest(b,c,d,...)   fills voids?
	others?

* server and modenv is an experimental system for GIS-based modelling
environment, the idea is to have a command line interface to GIS,
graphing (gnuplot, ...), RDBMS (via DBI), watching of values of
variables (implemented using IPC), and so on...

- combine small areas?

* map to accept ranges for integer and also float grids, i.e,
saying something like $g->map({[1.8,5.5]=>2); would map
all values in (float) grid which are in the range 1.8..5.5
to value 2 -- what kind of syntax?

* vector data in the case of a grid with no colortable?

* interpolation methods

* attribute data on vector data elements?

* much, much more test code

14.10.2004:

* to be removed eventually: all vector support? gdopen, gdsave
* integration with gdal? maybe not, gdal utility program can be used to convert
  to bil/hdr files
* method contents for floating point grids should be something else than what it is now
