readRAST6 {spgrass6} | R Documentation |
Read GRASS 6 raster files from GRASS 6 into R SpatialGridDataFrame objects, and write single columns of R SpatialGridDataFrame objects to GRASS 6. readRAST6
and writeRAST6
use temporary binary files and r.out.bin and r.in.bin rather than the temporary ASCII files used in earlier implementations. The earlier versions may still be used in a transition period.
readRAST6(vname, cat=NULL, ignore.stderr = FALSE) writeRAST6(x, vname, zcol = 1, NODATA=-9999, ignore.stderr = FALSE)
vname |
A vector of GRASS 6.0 raster file names |
cat |
default NULL; if not NULL, must be a logical vector matching vname, stating which (CELL) rasters to return as factor |
ignore.stderr |
default FALSE, can be set to TRUE to silence system() output to standard error; does not apply on Windows platforms |
x |
A SpatialGridDataFrame object for export to GRASS as a raster layer |
zcol |
Attribute column number or name |
NODATA |
NODATA value |
readRAST6
returns a SpatialGridDataFrame objects with an AttributeList in the data slots, and with the projection argument set.
Roger S. Bivand, e-mail: Roger.Bivand@nhh.no
if (nchar(Sys.getenv("GISRC")) > 0) { spear <- readRAST6(c("geology", "elevation.dem"), cat=c(TRUE, FALSE), ignore.stderr=TRUE) table(spear$geology) system("r.stats -q -cl geology") boxplot(spear$elevation.dem ~ spear$geology) spear$sqdem <- sqrt(spear$elevation.dem) writeRAST6(spear, "sqdemSP", zcol="sqdem", NODATA=-9999.99, ignore.stderr=TRUE) system("r.info sqdemSP") system("g.remove rast=sqdemSP") }