[GRASS-user] r.drain documentation

[Patton, Eric]

>I'm a bit confused about r.drain (I'm working with Debian's backport version
>6.2.1). I have noticed that if you give as input in the "coordinate"
>parameter a point that stands on the region's edge, r.drain won't "move"
>from there: it would output a map with that same single point. Is this a
>bug?
>On the other hand I can't understand why in the man page the section
>entitled BUG says: "r.drain currently finds only the lowest point (the cell
>having the smallest category value) in the input file that can be reached
>through directly adjacent cells that are less than or equal in value to the
>cell reached immediately prior to it; therefore, it will not necessarily
>reach the lowest point in the input file. It currently finds pits in the
>data, rather than the lowest point present.". Why would a local search be a
>bug in this case? I think it should be like that by design...
>I'm not too sure my understanding is correct. What do you think?
>Thanks a lot in advance,
>Stefano.

My short answer is I don't know; but I can try to have a look at the module and 
try to figure out what is happening...I've never used it before, so it will take
some trial-and-error to figure. Alternatively, if anyone listening is familiar with 
r.drain and can previde some hints, I'll certainly update the manpage.

~ Eric.