[R-sig-Geo] Flow accumulation in R?

[Stephen Sefick]

I would be very interested in your work of getting flow accumulation 
working in R.  I might be able to help (with my limited skills).

Stephen

On Thu 29 Sep 2011 01:50:10 PM CDT, Jonathan Greenberg wrote:
> Thanks for the responses -- one of the issues with the GRASS
> implementation of terraflow is that there is not, to my knowledge,
> parallel support for the code -- the C++ version, I suppose, we can
> try to compile, although it seems to be fairly out of date.  I figured
> with the quickly increasing capabilities in spatial programming beyond
> just spatial statistics in R (e.g. via raster, rgdal, maptools), as
> well as other people developing parallel interfaces for R (e.g.
> snowfall, Rmpi), R may do well as a scalable system for doing large
> scale image processing/GIS analyses.  Certainly, other programs have
> not scaled well (ArcMap and GRASS to name a few).
>
> topidx looked interesting but I can tell that it won't scale -- it
> requires the image be in memory as a matrix, so any reasonably large
> DEM won't work.
>
> Sounds like this may require some programming!
>
> --j
>
>
>
> On Thu, Sep 29, 2011 at 6:02 AM, Rich Shepard<rshepard at appl-ecosys.com>  wrote:
>> On Wed, 28 Sep 2011, Jonathan Greenberg wrote:
>>
>>> I was wondering if anyone had implemented flow accumulation in R (e.g.
>>> http://www.cs.duke.edu/geo*/terraflow/)?
>>
>> Jon,
>>
>>   I use r.terraflow (and other hydrological modules) within GRASS
>> <http://grass.osgeo.org/>. Terrain and hydrologic modeling is best done, in
>> my opinion, in GRASS and leave the spatial statistics to R. There is an
>> interface between the two that allows us users to take advantage of both.
>>
>> Rich
>>
>> --
>> Richard B. Shepard, Ph.D.          |   Integrity - Credibility - Innovation
>> Applied Ecosystem Services, Inc.   |    Helping Ensure Our Clients' Futures
>> <http://www.appl-ecosys.com>       Voice: 503-667-4517      Fax: 503-667-8863
>>
>
>
>