For supervised classification the advantage of R could be that you have more a more flexible algorithms available. I know some folks have been using RandomForest together with 'raster' so that you can do large files. You can have a look at the 'dismo' package which talks about species distribution modeling (but the flow of data analysis is the same for classification).
For unsupervised classification the R algorithms are nice too but they have data size limitations that cannot be solved by 'raster'. Robert On Wed, Nov 17, 2010 at 4:46 AM, Lucy Tallents <conservation...@btinternet.com> wrote: > Dear Malik, > > > > I'm a newcomer to GRASS and R myself, having recently moved over from > ArcGIS/Erdas, so I'm probably not the best person to assist you. My > suggestion was merely that it seems sensible to use a GIS software to do a > GIS task, particularly one such as classification which often requires a > large degree of interaction with the data to define training samples and > improve the classification iteratively. > Or do data analysis with data analysis software (such as R)? > > > I'm interested to hear opinions from others - is GRASS the best route for > land-cover classification, or are stand-alone packages in R a viable > alternative? Any advice would be much appreciated - thank you. > > > > Regarding the use of GRASS and R, my understanding is that you start R > through the GRASS terminal and then work in the usual R interface. This > presumably allows R to apply GRASS commands to the GIS layers in the > location & mapset you started GRASS in. This booting of R through GRASS is > briefly described at the end of the > http://grass.fbk.eu/statsgrass/grass6_r_install.html. > > > > If you need help in installing the xml package (from the list, not from > newbie me!), you would need to provide more information about your setup > (operating system/R version), what method you used to install (download zip > file, install directly through R?), and the precise error message. However, > I strongly suggest that you use the online help and maillist archives to try > and find your answer before sending a request to the list. > > > > I hope that helps - other readers please do feel free to correct any errors > or omissions of mine. > > > > Best wishes, > > > > Lucy > > > > From: Malik Shahzad [mailto:geoma...@live.com] > Sent: 17 November 2010 08:24 > To: conservation...@btinternet.com > Subject: RE: [R-sig-Geo] Package for Classification???? > > > > Dear Dr. Lucy! > > > > Thanks for your kind help. As per your instructions I tried to install > GRASS. Then I tried to load package "spgrass6" in R and found error: > > Need "XML" Package and I am unable to install XML package for windows... > from > > http://cran.r-project.org/web/packages/XML <http://> > > > > Second, I will work in R-Interface after loading GRASS package or I have to > work in GRASS Interface??? > > > > Please help me in this regards, As I am new in both packages... & once again > thanks... > > with Best Regards, > > Malik Shahzad > Visiting Researcher > National Institute of Informatics (NII) > Tokyo, Japan > > Doctoral Student > Asian Institute of Technology (AIT) > Bangkok, Thailand > +66-8-7676-5616 > > > > > _____ > > From: conservation...@btinternet.com > To: geoma...@live.com > Subject: RE: [R-sig-Geo] Package for Classification???? > Date: Tue, 16 Nov 2010 16:21:36 +0000 > > Dear Malik, > > > > Using the GRASS-R interface would seem to be a sensible route. See: > > > > http://cran.r-project.org/web/packages/spgrass6/index.html > > http://grass.fbk.eu/statsgrass/grass6_r_install.html > > > > Best wishes, > > > > Lucy > > > > > > Dr Lucy Tallents > > Assistant Coordinator, PG Dip in International Wildlife Conservation > Practice > > > > Wildlife Conservation Research Unit (WildCRU) > > Zoology, University of Oxford > > The Recanati-Kaplan Centre > > Tubney House, Abingdon Road > > Tubney, Abingdon OX13 5QL, UK > > T +44 (0) 1865 611125 > > F +44 (0) 1865 611101 > > M +44 (0) 7763 378147 > > <http://www.wildcru.org/diploma> www.wildcru.org/diploma > > > > > > > > From: r-sig-geo-boun...@stat.math.ethz.ch > [mailto:r-sig-geo-boun...@stat.math.ethz.ch] On Behalf Of Malik Shahzad > Sent: 16 November 2010 16:16 > To: R Help > Subject: [R-sig-Geo] Package for Classification???? > > > > > > Dear I want to know a good package for Raster data classification ( > Supervised & Unsupervised).Thanks in Advance... > > with Best Regards, > > > > Malik Shahzad > > Visiting Researcher > > National Institute of Informatics (NII) > > Tokyo, Japan > > > > Doctoral Student > > Asian Institute of Technology (AIT) > > Bangkok, Thailand > > +66-8-7676-5616 > > > > [[alternative HTML version deleted]] > > _______________________________________________ > R-sig-Geo mailing list > R-sig-Geo@stat.math.ethz.ch > https://stat.ethz.ch/mailman/listinfo/r-sig-geo > > > > _____ > > No virus found in this message. > Checked by AVG - www.avg.com > > > > [[alternative HTML version deleted]] > > _______________________________________________ > R-sig-Geo mailing list > R-sig-Geo@stat.math.ethz.ch > https://stat.ethz.ch/mailman/listinfo/r-sig-geo > _______________________________________________ R-sig-Geo mailing list R-sig-Geo@stat.math.ethz.ch https://stat.ethz.ch/mailman/listinfo/r-sig-geo
