r.los and r.drain

[Malcolm Williamson]

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 option
> 
> ERROR: 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 at 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