[GRASS5] Angle of incidence in viewshed/line of sight

[benducke at compuserve.de]

Well, I have done some experimenting installing binaries
on different systems
and found that it works better than I expected.
Most Linux distributions in use today are pretty compatible
regarding basic system libs and since newer version of those
libs are usually backward copatible, one could compile
a version on an older system and newer once should be able
to run it.
I expect even less trouble from MacOS and Windows;
cross-compilers for these plattforms seem to be available
for Linux.
Basically, once the final GRASS 6 gets out, it should
be possible to provide binaries of add-on C modules,
that can just be copied into /usr/local/grass/bin or
wherever the user installed to.

I am still working on getting things to compile from
source outside the GRASS source tree.
For this to work, I have to re-arrange a lot of my source
code. Since I have been busy with other coding these
last weeks, there is no progress here, but it is the
next thing I am going to look into.

Regards,

Benjamin.

----- Originalnachricht -----
Von: Michael Barton <michael.barton at asu.edu>
Datum: Dienstag, 8. März 2005 6:51 am
Betreff: Re: [GRASS5] Angle of incidence in viewshed/line of sight

> Benjamin,
> 
> How are you coming on a way to install code like this without 
> compiling or
> recompiling GRASS?
> 
> Michael
> ____________________
> C. Michael Barton, Professor of Anthropology
> School of Human Evolution and Social Change
> PO Box 872402
> Arizona State University
> Tempe, AZ  85287-2402
> USA
> 
> Phone: 480-965-6262
> Fax: 480-965-7671
> www: <www.public.asu.edu/~cmbarton>
> 
> 
> > From: Benjamin Ducke <benducke at compuserve.de>
> > Organization: FU Berlin
> > Date: Thu, 3 Mar 2005 21:33:12 +0100
> > To: <grass5 at grass.itc.it>
> > Subject: Re: [GRASS5] Angle of incidence in viewshed/line of sight
> > 
> > On Wed, 2 Mar 2005 13:28:14 +1300
> > Hamish <hamish_nospam at yahoo.com> wrote:
> > 
> >>> Just so we don't re-invent the wheel, has anyone developed the 
> code>>> for evaluating the angle of incidence from a single point 
> in the
> >>> landscape (i.e. the point used for r.los) to cells within the
> >>> viewshed? I am analyzing repeated historical topographic survey
> >>> photographs (more on this later) and want to account for 
> components of
> >>> registration and classification error due to terrain (angle of
> >>> incidence). I have looked at the code for r.los and r.sun and 
> will be
> >>> seeking help from some students in our new computer 
> science/geomatics>>> programme as I am not (yet) a programmer. Look 
> forward to any
> >>> suggestions...
> >> 
> >> 
> >> Yes, I have done this some time ago.
> >> 
> >> I modified r.los to return horizontal angle to target instead of
> >> vertical angle to target for the values in the resultant raster 
> map. This
> >> was for GRASS 5.0, but it should work for 6.0 just as well I 
> think. If
> >> you want I can supply the code.
> >> 
> >> r.los is a real mess and doesn't scale well to larger grid sizes.
> >> 
> >> Be sure to check out r.cva as well:
> >>   http://www.ucl.ac.uk/~tcrnmar/GIS/r.cva.html
> >> 
> > 
> > The GRASS 5 version of r.cva is currently broken due to a bug
> > in the floating point raster code I introduced myself (ahem).
> > I will have finished an updated version for GRASS 6 next week
> > that fixes the bug, handles vector points for observer positions
> > and introduces attributes for observer positions just
> > like Argh!nfo's Spatial Analyst uses.
> > I'll ask Mark Lake to update the file on his webpage then.
> > 
> > Regards,
> > 
> > Benjamin.
> > 
> > 
> > 
> >> 
> >> r.sunmask with altitude and azimuth options might be another way.
> >> 
> >> 
> >> 
> >> Hamish
> >> 
> >> _______________________________________________
> >> grass5 mailing list
> >> grass5 at grass.itc.it
> >> http://grass.itc.it/mailman/listinfo/grass5
> > 
> 
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