GDALReadOnlyDataset-methods {rgdal} | R Documentation |
subsets GDAL objects, returning a SpatialGridDataFrame object
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:
the other arguments, offset
and region.dim
are
derived from row/column selection values.
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 J. Pebesma
See also readGDAL
GDALDriver-class
,
GDALDataset-class
, GDALTransientDataset-class
,
SpatialGridDataFrame-class
.
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)