Bryant,
You are misinterpreting the usage for these GRASS commands:
(lines deleted)
When trying r.los:
Mapset <PERMANENT> in Location <BASIN>
GRASS 4.0 > r.los dem2 los2 763830,4321140
Sorry <los2> is not a valid option
Sorry <763830,4321140> is not a valid optionERROR: Required parameter <output> not set:
(Raster map name for storing results).ERROR: Required parameter <coordinate> not set:
(Coordinate identifying the viewing location).Usage:
r.los input=name output=name coordinate=x,y [patt_map=name]
[obs_elev=value] [max_dist=value]
Your command line should read: r.los input=dem2 output=los2 coordinate=763830,4321140
The same logic holds true for r.drain, and most, if not all, of the other
GRASS commands. Good luck!
----------------
Malcolm D. Williamson - Technical Assistant E-mail: malcolm@cast.uark.edu
Center for Advanced Spatial Technologies Telephone: (501) 575-5736
Ozark Rm. 214 Fax: (501) 575-3846
University of Arkansas
Fayetteville, AR 72701