Dear Adam, Thanks for reporting this bug in the current version of raster (1.9-92). You have identified a valid work-around:
rasvals<-raster:::.polygonsToRaster(gSRDF, rasdef, field=gSRDF$TotPop90) or rasvals<-raster:::.polygonsToRaster(gSRDF, rasdef, field='TotPop90') The bug occurs because rasterize has these arguments: function(x, y, field, ...) and then calls polygonsToRaster(x, y, ...) 'field' should either not be an argument, or it should be passed on to .polygonsToRaster Robert On Sun, May 13, 2012 at 7:28 PM, Adam Slez <as...@princeton.edu> wrote: > I'm using the rasterize command in the raster package to rasterize polygon > data and can't seem to get the rasterize routine to recognize the field > parameter. Here's a working example which illustrates the problem: > > #load libraries > library(raster) > library(spgwr) > > #load data > data(georgia) > > #confirm TotPop90 values > range(gSRDF$TotPop90) > > #build raster data > rasdef<-raster(extent(gSRDF), nrow = 100, ncol = 100) > rasvals<-rasterize(gSRDF, rasdef, field = gSRDF$TotPop90) > rasvals > > If we compare the minimum and maximum values reported in the rasvals output > to the values reported in the range(gSRDF$TotPop90), it is clear that they > aren't the same. Simply put, the rasterize command seems to be spitting > out the observation numbers rather than the values associated with the > TotPop90 variable. > > In the case of SpatialPolygon data, the values input via the field > parameter are passed to the .polygonsToRaster function. Playing around > with this, I've discovered that I get the expected results by doing the > following: > > rasvals<-raster:::.polygonsToRaster(gSRDF, rasdef, gSRDF$TotPop90) > > Any thoughts as to why I can't do this using rasterize in the usual way? > > Adam > > [[alternative HTML version deleted]] > > _______________________________________________ > R-sig-Geo mailing list > R-sig-Geo@r-project.org > https://stat.ethz.ch/mailman/listinfo/r-sig-geo > [[alternative HTML version deleted]] _______________________________________________ R-sig-Geo mailing list R-sig-Geo@r-project.org https://stat.ethz.ch/mailman/listinfo/r-sig-geo
