On Fri, Jul 20, 2012 at 4:51 PM, Celine <bellard.cel...@gmail.com> wrote: > Hi, > > I am working with a SpatialPolygonsDataFrame of many islands. There are a > lot of polygons (islands) composing my SpatialPolygonsDataFrame. > I want to extract the elevation of each island.
Is each island a row in your SPDF? Or is it just one row, with lots of island polygons? What does dim(hot) (assuming 'hot' is your SPDF) say? > I need to separate the different polygons (like dissolve function in > arcgis), to have the elevation of each island. If each island is a row, then its easy, if each island is a separate loop in a single row, a bit trickier. How are you going to get the elevation? Do you have a separate data source, such as a grid of elevations? Also, try hopping over to the R-sig-geo mailing list. For everything spatial. Barry blog: http://geospaced.blogspot.com/ web: http://www.maths.lancs.ac.uk/~rowlings web: http://www.rowlingson.com/ twitter: http://twitter.com/geospacedman pics: http://www.flickr.com/photos/spacedman ______________________________________________ R-help@r-project.org mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide http://www.R-project.org/posting-guide.html and provide commented, minimal, self-contained, reproducible code.
