An object inheriting from class 'GDALReadOnlyDataset'
band
The band number (1-based) to read from
offset
Number of rows and columns from the origin (usually the
upper left corner) to begin reading from; presently ordered (y,x) - this may change
region.dim
The number of rows and columns to read from the
dataset; presently ordered (y,x) - this may change
output.dim
Number of rows and columns in the output data; if
smaller than region.dim the data will be subsampled
interleave
Element and row stride while reading data; rarely
needed
as.is
If false, scale the data to its natural units; if the
case of thematic data, return the data as factors
list_out
default FALSE, return array, if TRUE, return a list of vector bands
raster
An object of class GDALRasterBand
x
integer variable for conversion
base
If Byte input, 8, if Int16 or UInt16, 16
OVERRIDE_PROJ_DATUM_WITH_TOWGS84
logical value, default NULL, which case the cached option set by set_OVERRIDE_PROJ_DATUM_WITH_TOWGS84 is used. Ignored if the GDAL version is less than “1.8.0” or if the CPLConfigOption variable is already set
value
logical value to set OVERRIDE_PROJ_DATUM_WITH_TOWGS84
Details
getRasterData:
retrieves data from the dataset as an array or list of bands; will try to convert relevant bands to factor if category names are available in the GDAL driver when returning a list.
getRasterTable:
retrieves data from the dataset as data frame.
getProjectionRef:
returns the geodetic projection in
Well Known Text format.
getRasterBand:
returns a raster band
getRasterBlockSize:
returns the natural block size of
the raster band. Use this for efficient tiled IO.
toSigned:
used to convert a band read as unsigned integer to signed integer
toUnSigned:
used to convert a band read as signed integer to unsigned integer
Objects from the Class
Objects can be created by calls of the form new("GDALRasterBand", dataset, band).
Slots
handle:
Object of class "externalptr", from class "GDALMajorObject", used internally; not for public consumption
Extends
Class "GDALMajorObject", directly.
Methods
dim
signature(x = "GDALRasterBand"): ...
initialize
signature(.Object = "GDALRasterBand"): ...
Note
The OVERRIDE_PROJ_DATUM_WITH_TOWGS84 argument is used to revert GDAL behaviour to pre-1.8.0 status; from 1.8.0, any input datum may be discarded if the input also includes a towgs84 tag in conversion to the PROJ.4 representation, see http://trac.osgeo.org/gdal/ticket/4880 and http://lists.osgeo.org/pipermail/gdal-dev/2012-November/034550.html. The cached value of OVERRIDE_PROJ_DATUM_WITH_TOWGS84 will also be used in open.SpatialGDAL, sub.GDROD, and asGDALROD_SGDF, which do not have a suitable argument
Author(s)
Timothy H. Keitt, modified by Roger Bivand
See Also
See also GDALDriver-class, GDALDataset-class, GDALTransientDataset-class
Examples
logo <- system.file("pictures/logo.jpg", package="rgdal")[1]
x <- new("GDALReadOnlyDataset", logo)
plot(density(getRasterTable(x)$band1))
GDAL.close(x)