Package for Classification????
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
<conservationgis at 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:geomalik at live.com] Sent: 17 November 2010 08:24 To: conservationgis at 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: conservationgis at btinternet.com To: geomalik at 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-bounces at stat.math.ethz.ch [mailto:r-sig-geo-bounces at 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]]
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