SAGA has a module to convert from shapes to grids (GRASS can do the same).
See: > library(RSAGA) > rsaga.get.usage(lib="grid_gridding", module=0) SAGA CMD 2.0.3 library path: C:/Progra~1/saga_vc/modules library name: grid_gridding module name : Shapes to Grid Usage: 0 [-GRID <str>] -INPUT <str> [-FIELD <num>] [-TARGET_TYPE <num>] [-LINE_TYPE <num>] [-USER_CELL_SIZE <str>] [-USER_FIT_EXTENT] [-USER_X_EXTENT_MIN <str>] [-USER_X_EXTENT_MAX <str>] [-USER_Y_EXTENT_MIN <str>] [-USER_Y_EXTENT_MAX <str>] [-USER_GRID_TYPE <num>] [-GET_SYSTEM_SYSTEM_NX <num>] [-GET_SYSTEM_SYSTEM_NY <num>] [-GET_SYSTEM_SYSTEM_X <str>] [-GET_SYSTEM_SYSTEM_Y <str>] [-GET_SYSTEM_SYSTEM_D <str>] [-GET_SYSTEM_GRID_TYPE <num>] [-GRID_GRID <str>] -GRID:<str> Grid Data Object (optional output) -INPUT:<str> Shapes Shapes (input) -FIELD:<num> Attribute ... Here is an example: ... # first, convert the contour map to a raster map: > rsaga.geoprocessor(lib="grid_gridding", module=3, > param=list(GRID="contours_buff.sgrd", + INPUT="z_contours.shp", FIELD=1, LINE_TYPE=0, USER_CELL_SIZE=dem.pixelsize, + user_x_extent_min=elevati...@bbox[1,1], user_x_extent_max=elevati...@bbox[1,2], + user_y_extent_min=elevati...@bbox[2,1], user_y_extent_max=elevati...@bbox[2,2])) # now extract a buffer distance map (for 'contours') and load it back to R: # the parameters DIST and IVAL are estimated based on the grid properties: > rsaga.geoprocessor(lib="grid_tools", module=10, > param=list(SOURCE="contours_buff.sgrd", + DISTANCE="contours_dist.sgrd", ALLOC="contours_alloc.sgrd", BUFFER="contours_bdist.sgrd", + DIST=sqrt(dem.area)/3, IVAL=dem.pixelsize)) > rsaga.sgrd.to.esri(in.sgrds="contours_dist.sgrd", > out.grids="contours_dist.asc", + out.path=getwd(), prec=1) > contours.dist <- readGDAL("contours_dist.asc") > spplot(contours.dist[1], col.regions=bpy.colors(), scales=list(draw=TRUE), + sp.layout=list("sp.lines", col="cyan", z.contours)) > hist(contours.dist$band1, col="grey") ... HTH T. Hengl http://spatial-analyst.net/wiki/index.php?title=Grid_size_calculator > -----Original Message----- > From: r-sig-geo-boun...@stat.math.ethz.ch > [mailto:r-sig-geo-boun...@stat.math.ethz.ch] On Behalf > Of Jonathan Greenberg > Sent: Sunday, August 02, 2009 8:26 PM > To: r-sig-geo@stat.math.ethz.ch > Subject: [R-sig-Geo] Polygon to raster? > > I'm trying to hunt down a function that will take a polygon (derived > from a shapefile) and "rasterize" it at a given pixel resolution -- any > hints? > > --j > > -- > > Jonathan A. Greenberg, PhD > Postdoctoral Scholar > Center for Spatial Technologies and Remote Sensing (CSTARS) > University of California, Davis > One Shields Avenue > The Barn, Room 250N > Davis, CA 95616 > Cell: 415-794-5043 > AIM: jgrn307, MSN: jgrn...@hotmail.com, Gchat: jgrn307 > > _______________________________________________ > 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