Markus,<br>
<br>
Thanks for the input. I reviewed the r.sun page and unfortunately r.sun
doesn't provide the specific horizon angle provided by r.horizon. My
goal is not to compute solar irradiance.<br>
<br>
I was able to run r.horizon on a subset that was ~4900x9900. The DEM
I'm trying to use in 30000x78000 (but is has quite a bit of null
values). <br>
<br>
Do you know if there is pixel dimension limit to r.horizon?<br>
<br>
I am using the 64-bit package available through the Ubuntu site -- would it make a difference if I built the code from source?<br>
<br>
Do anyone know of a script that would iteratively set a region, compute
r.horizon (with a buffer), move the region, and r.patch the resulting
horizon files?<br>
If anyone is interested in writing this script, we could discuss compensation (contact directly at jcampbell.geo at <a href="http://gmail.com">gmail.com</a>)<br>
<br>
Thanks,<br>
Josh<br><br><font color="#888888">Joshua Campbell<br>Kansas Applied Remote Sensing Program<br>University of Kansas<br>Lawrence, KS<br><br></font><div class="gmail_quote">On Sun, Nov 29, 2009 at 3:13 PM, Markus Neteler <span dir="ltr"><<a href="mailto:neteler@osgeo.org">neteler@osgeo.org</a>></span> wrote:<br>
<blockquote class="gmail_quote" style="border-left: 1px solid rgb(204, 204, 204); margin: 0pt 0pt 0pt 0.8ex; padding-left: 1ex;"><div class="im">On Mon, Nov 23, 2009 at 8:05 PM, Joshua Campbell<br>
<<a href="mailto:jcampbell.geo@gmail.com">jcampbell.geo@gmail.com</a>> wrote:<br>
> I have been trying to run r.horizon on a SRTM DEM for the continental US,<br>
> with no success. The operation runs for about 45 minutes then eventually<br>
> just stops with no warnings or errors<br>
><br>
> I'm running GRASS 6.4-rc5 64-bit in Ubuntu 9.10 on a virtual machine<br>
> (Virtual Box on Windows XP 64-bit).<br>
><br>
> The r.horizon function will consume as much RAM as apply to the machine, up<br>
> to 6144 MB, plus an additional 4GB of swap memory.<br>
><br>
> The DEM is in Geographic coordinates - WGS 84. I tried to run r.horizon in<br>
> only 1 direction with maximum distance of 5310 meters.<br>
><br>
> Is there a file size limitation? Or any suggestions for an optimal size?<br>
<br>
</div>Do you really want r.horizon or do you want it as input for r.sun?<br>
If so, see also here:<br>
<a href="http://grass.osgeo.org/wiki/Rsun" target="_blank">http://grass.osgeo.org/wiki/Rsun</a><br>
<br>
I recently used r.sun without r.horizon and it took way less RAM.<br>
<font color="#888888"><br>
Markus<br>
</font></blockquote></div><br>