r.cost for dummies

[bob at math.umn.edu]

... which is to say, me.

I managed to get through the first part of the GRASS Seeds Optimal 
Routing exercise, up to step 7, by r.patch-ing zeros into the asp_south
and asp_north maps, covering up the "no data" cells which had caused
r.mapcalc problems.  Looks like r.mapcalc might need a flag to indicate
it should treat "no data" as zeros, or not.

In doing

   r.cost input=cost coord=445775,310875 output=cost_dist

the output file is present, yet full of "no data."  This happens with and
without the -k options, and under command line and interactive modes.  As
the input map and the coord (BTW it failed when I used "coordinate" as 
well) are not "no data" this is confusing.

RSVP if you have any clues.  I'm fresh out.  :^)

Adios,
Chris
-- 
C.S. Cornuelle 
School of Mathematics/MCIM
206 Church St. SE
University of Minnesota
Minneapolis, MN 55455
(612) 626-8930, 624-9069
bob at math.umn.edu
--
Ferventer Vestite