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parallel support for the code -- the C++ version, I suppose, we can try to compile, although it seems to be fairly out of date.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 <rshep...@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 > -- Jonathan A. Greenberg, PhD Assistant Professor Department of Geography University of Illinois at Urbana-Champaign 607 South Mathews Avenue, MC 150 Urbana, IL 61801 Phone: 415-763-5476 AIM: jgrn307, MSN: jgrn...@hotmail.com, Gchat: jgrn307, Skype: jgrn3007 http://www.geog.illinois.edu/people/JonathanGreenberg.html _______________________________________________ R-sig-Geo mailing list R-sig-Geo@r-project.org https://stat.ethz.ch/mailman/listinfo/r-sig-geo