[GRASS-user] r.horizon: gives only elevations of 0 in all directions using Grass demo data

[Markus Neteler]

Tom,

sorry for the late reply.

On Mon, Sep 8, 2014 at 10:37 AM,  <ttessier at solaradata.com> wrote:
> Hello,
>
> Using Grass 6.4.4 on Windows 7 on one computer and on Windows XP on
> another computer, we are only getting elevations to the horizon of
> 0.00000,-0.000000 at all angles. We are using the elevation models
> included in the demonstration sites for North Carolina and South Dakota.
> Tried many combinations of input and always receive the zeros as the
> answer. In one case, I tried putting in the same input as in the manual
> page for r.horizon:
>
> r.horizon elevin=elevation direction=215 horizonstep=0 bufferzone=200
> coord=638871.6,223384.4
>
> Still produces zeros. Any ideas?

Are you sure that the computational region was right? I get results:

GRASS 6.4.4svn (nc_spm_08):~ > g.region rast=elevation -p
projection: 99 (Lambert Conformal Conic)
zone:       0
datum:      nad83
ellipsoid:  a=6378137 es=0.006694380022900787
north:      228500
south:      215000
west:       630000
east:       645000
nsres:      10
ewres:      10
rows:       1350
cols:       1500
cells:      2025000
GRASS 6.4.4svn (nc_spm_08):~ > r.horizon elevin=elevation
direction=215 horizonstep=0 bufferzone=200 coord=638871.6,223384.4
215.000000, 0.068388


GRASS 7.0.0svn (nc_spm_08_grass7):~ > g.region rast=elevation -p
projection: 99 (Lambert Conformal Conic)
zone:       0
datum:      nad83
ellipsoid:  a=6378137 es=0.006694380022900787
north:      228500
south:      215000
west:       630000
east:       645000
nsres:      10
ewres:      10
rows:       1350
cols:       1500
cells:      2025000
GRASS 7.0.0svn (nc_spm_08_grass7):~ > r.horizon elevin=elevation
direction=215 horizonstep=0 bufferzone=200 coord=638871.6,223384.4
azimuth,horizon_height
215.000000,0.068388

Markus