In my previous post I happily handled the binary National Snow and Ice Data Center sea ice imagery and cast it into a GeoTiff. My next challenge is to wrap the GeoTiff into a kml overlay. Continuing the code from the previous post, I pick it up just after writing the raster object to the geoTiff.
... rr <- writeRaster(rr, geoTiffFile) >From there I sought to use the maptools package functions GE_SpatialGrid and kmlOverlay to create the kml, but first I needed to cast my raster into a spatial points dataframe and project to geographic coordinates. spdf <- rasterToPoints(rr, fun=NULL, spatial=TRUE) ## cast as a spatial points data frame xyWGS84 <- project(coordinates(spdf), inv=TRUE, proj=prj) ## Project to WGS84 geographic But this generates an error: Traceback: 1: .C("project_inv", as.integer(nc), as.double(xy[, 1]), as.double(xy[, 2]), x = double(nc), y = double(nc), proj, NAOK = TRUE, PACKAGE = "rgdal") 2: project(coordinates(spdf), inv = TRUE, proj = prj) Error in project(coordinates(spdf), inv = TRUE, proj = prj) : caught access violation - continue with care Apparently rgdal's project function is failing to invert the projection from the NSIDC projection, here referenced as prj <- CRS('+proj=stere +lat_0=90 +lat_ts=70 +lon_0=-45 +k=1 +x_0=0 +y_0=0 +a=6378273 +b=6356889.449 +units=m +no_defs') Any suggestions? ----- Tony Fischbach, Wildlife Biologist Walrus Research Program Alaska Science Center U.S. Geological Survey 4210 University Drive Anchorage, AK 99508-4650 afischb...@usgs.gov http://alaska.usgs.gov/science/biology/walrus -- View this message in context: http://r-sig-geo.2731867.n2.nabble.com/Reading-National-Snow-and-Ice-Data-Center-binary-files-tp6882737p6909541.html Sent from the R-sig-geo mailing list archive at Nabble.com. _______________________________________________ R-sig-Geo mailing list R-sig-Geo@r-project.org https://stat.ethz.ch/mailman/listinfo/r-sig-geo