GDALReadOnlyDataset-methods {rgdal} | R Documentation

## subset methods for "GDALReadOnlyDataset"

### Description

subsets GDAL objects, returning a SpatialGridDataFrame object

### Details

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:

as.is
  see getRasterData
interleave
  see getRasterData
output.dim
  see getRasterData

the other arguments, `offset` and `region.dim` are derived from row/column selection values.

### Methods

"["
  `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

### Author(s)

Edzer J. Pebesma

### See Also

See also `readGDAL` `GDALDriver-class`, `GDALDataset-class`, `GDALTransientDataset-class`, `SpatialGridDataFrame-class` .

### Examples

    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)

[Package rgdal version 0.4-4 Index]