[R-sig-Geo] Adding smoothing factor to terrain function in raster

[Alex Zvoleff]

Whoops - somehow a double comma worked its way into the ."Call" lines
in the first patch I sent. The attached patch is updated to address
that issue.

Alex

On Fri, May 30, 2014 at 10:48 AM, Alex Zvoleff
<azvoleff at conservation.org> wrote:
> Dear list (and Robert Hijmans in particular),
>
> I am using  the terrain function in the raster package to calculate
> slope and aspect prior to performing topographic correction. The
> landsat package supports applying a smoothing factor during the slope
> calculation, to avoid over-correction of reflectance in high slope
> areas with low illumination (as suggested by Riaño, Salas, and Aguado
> 2003). However I have been using the terrain function in the raster
> package to calculate slope and aspect since it can handle large
> rasters and is coded in C.
>
> Attached is a patch to allow applying a smoothing factor when
> calculating slope using the terrain function in raster. Is there a
> chance of including the attached changes (based on r2994) in the next
> release of raster?
>
> Thanks,
> Alex
>
> Ref: Riaño D., Chuvieco E., Salas J., and Aguado I., 2003. Assessment
> of different topographic corrections in Landsat-TM data for mapping
> vegetation types. IEEE Transactions on Geoscience and Remote Sensing
> 41: 1056-1061.
>
> --
> Alex Zvoleff
> Postdoctoral Associate
> Tropical Ecology Assessment and Monitoring (TEAM) Network
> Conservation International
> 2011 Crystal Dr. Suite 500, Arlington, Virginia 22202, USA
> Tel: +1-703-341-2749, Fax: +1-703-979-0953, Skype: azvoleff
> http://www.teamnetwork.org | http://www.conservation.org



-- 
Alex Zvoleff
Postdoctoral Associate
Tropical Ecology Assessment and Monitoring (TEAM) Network
Conservation International
2011 Crystal Dr. Suite 500, Arlington, Virginia 22202, USA
Tel: +1-703-341-2749, Fax: +1-703-979-0953, Skype: azvoleff
http://www.teamnetwork.org | http://www.conservation.org
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