subset methods for "GDALReadOnlyDataset"
subsets GDAL objects, returning a SpatialGridDataFrame object
The [ method subsets a GDAL data set, returning a SpatialGridDataFrame object. Reading is
done on the GDAL side, and only the subset requested is ever read into memory.
Further named arguments to [ are to either getRasterTable or getRasterData:
see getRasterData
see getRasterData
see getRasterData
the other arguments, offset and region.dim are
derived from row/column selection values.
An GDALReadOnlyDataset object can be coerced directly to a SpatialGridDataFrame
signature(.Object = "GDALReadOnlyDataset"): requires package
sp; selects rows and columns, and returns an object of class SpatialGridDataFrame
if the grid is not rotated, or else of class SpatialPointsDataFrame. Any arguments
passed to getRasterData (or in case of rotation getRasterTable) may be passed as
named arguments; the first three unnamed arguments are row,col,band
Edzer Pebesma
library(grid)
logo <- system.file("pictures/logo.jpg", package="rgdal")[1]
x <- new("GDALReadOnlyDataset", logo)
dim(x)
x.sp = x[20:50, 20:50]
class(x.sp)
summary(x.sp)
spplot(x.sp)
GDAL.close(x)
logo <- system.file("pictures/Rlogo.jpg", package="rgdal")[1]
x.gdal <- new("GDALReadOnlyDataset", logo)
x = x.gdal[,,3]
dim(x)
summary(x)
spplot(x)
spplot(x.gdal[])
GDAL.close(x.gdal)
logo <- system.file("pictures/Rlogo.jpg", package="rgdal")[1]
x.gdal <- new("GDALReadOnlyDataset", logo)
x.as <- as(x.gdal, "SpatialGridDataFrame")
GDAL.close(x.gdal)
summary(x.as)Please choose more modern alternatives, such as Google Chrome or Mozilla Firefox.