Class for spatial attributes that have spatial locations on a (full) regular grid on file, not (yet) actually read.

# S3 method for SpatialGDAL
open(con, ..., silent = FALSE, allowedDrivers = NULL, options=NULL)
# S3 method for SpatialGDAL
close(con, ...)
copy.SpatialGDAL(dataset, fname, driver = getDriver(dataset@grod),
 strict = FALSE, options = NULL, silent = FALSE)

Arguments

con

file name of grid map for opening, SpatialGDAL object for closing

...

other arguments (currently ignored)

silent

logical; if TRUE, comment and non-fatal CPL driver errors suppressed

dataset

object of class SpatialGDAL

fname

file name of grid map

driver

GDAL driver name

strict

TRUE if the copy must be strictly equivalent, or more normally FALSE indicating that the copy may adapt as needed for the output format

allowedDrivers

a character vector of suggested driver short names may be provided starting from GDAL 2.0

options

driver-specific options to be passed to the GDAL driver; only available for opening datasets from GDAL 2.0

Objects from the Class

Objects can be created by calls of the form open. SpatialGDAL(name), , where name is the name of the GDAL file.

Slots

points:

see SpatialPoints; points slot which is not actually filled with all coordinates (only with min/max)

grid:

see GridTopology-class; grid parameters

grid.index:

see SpatialPixels-class; this slot is of zero length for this class, as the grid is full

bbox:

Object of class "matrix"; bounding box

proj4string:

Object of class "CRS"; projection

data:

Object of class data.frame, containing attribute data

Extends

Class Spatial-class, directly.

Methods

[

signature(x = "SpatialGDAL", i, j, ...): selects rows (i), columns (j), and bands (third argument); returns an object of class SpatialGridDataFrame-class. Only the selection is actually read.

[[

signature(i): reads band i and returns the values as a numeric vector

Note

Non-fatal CPL errors may be displayed for some drivers, currently for the AIG ArcInfo 9.3 binary raster driver using GDAL >= 1.6.2; the data has been read correctly, but the contents of the info directory did not meet the specifications used to reverse engineer the driver used in GDAL (see https://trac.osgeo.org/gdal/ticket/3031)

Author

Edzer Pebesma, edzer.pebesma@uni-muenster.de

See also

SpatialGridDataFrame-class, which is actually sub-classed.

Examples

x <- open.SpatialGDAL(system.file("external/test.ag", package="sp")[1])
#> /home/rsb/lib/r_libs/sp/external/test.ag has GDAL driver AAIGrid #> and has 115 rows and 80 columns
image(x[])
image(as(x, "SpatialGridDataFrame"))
summary(as(x, "SpatialGridDataFrame"))
#> Object of class SpatialGridDataFrame #> Coordinates: #> min max #> x 178400 181600 #> y 329400 334000 #> Is projected: NA #> proj4string : [NA] #> Grid attributes: #> cellcentre.offset cellsize cells.dim #> x 178420 40 80 #> y 329420 40 115 #> Data attributes: #> band1 #> Min. : 128.4 #> 1st Qu.: 293.2 #> Median : 371.4 #> Mean : 423.2 #> 3rd Qu.: 499.8 #> Max. :1805.8 #> NA's :6097
spplot(as(x, "SpatialGridDataFrame"))
# select first 50 rows: summary(x[1:50])
#> Object of class SpatialGridDataFrame #> Coordinates: #> min max #> x 178400 181600 #> y 332000 334000 #> Is projected: NA #> proj4string : [NA] #> Grid attributes: #> cellcentre.offset cellsize cells.dim #> x 178420 40 80 #> y 332020 40 50 #> Data attributes: #> band1 #> Min. : 186.9 #> 1st Qu.: 307.2 #> Median : 393.5 #> Mean : 482.4 #> 3rd Qu.: 601.3 #> Max. :1805.8 #> NA's :3113
# select first 50 columns: summary(x[,1:50])
#> Object of class SpatialGridDataFrame #> Coordinates: #> min max #> x 178400 180400 #> y 329400 334000 #> Is projected: NA #> proj4string : [NA] #> Grid attributes: #> cellcentre.offset cellsize cells.dim #> x 178420 40 50 #> y 329420 40 115 #> Data attributes: #> band1 #> Min. : 130.3 #> 1st Qu.: 295.1 #> Median : 385.7 #> Mean : 437.4 #> 3rd Qu.: 520.0 #> Max. :1805.8 #> NA's :3629
# select band 1: summary(x[,,1])
#> Object of class SpatialGridDataFrame #> Coordinates: #> min max #> x 178400 181600 #> y 329400 334000 #> Is projected: NA #> proj4string : [NA] #> Grid attributes: #> cellcentre.offset cellsize cells.dim #> x 178420 40 80 #> y 329420 40 115 #> Data attributes: #> band1 #> Min. : 128.4 #> 1st Qu.: 293.2 #> Median : 371.4 #> Mean : 423.2 #> 3rd Qu.: 499.8 #> Max. :1805.8 #> NA's :6097
# select first 50 rows, first 50 columns, band 1: summary(x[1:50,1:50,1])
#> Object of class SpatialGridDataFrame #> Coordinates: #> min max #> x 178400 180400 #> y 332000 334000 #> Is projected: NA #> proj4string : [NA] #> Grid attributes: #> cellcentre.offset cellsize cells.dim #> x 178420 40 50 #> y 332020 40 50 #> Data attributes: #> band1 #> Min. : 275.0 #> 1st Qu.: 590.4 #> Median : 740.5 #> Mean : 797.6 #> 3rd Qu.: 928.9 #> Max. :1805.8 #> NA's :2338
# get values of first band: summary(x[[1]])
#> Min. 1st Qu. Median Mean 3rd Qu. Max. NA's #> 128.4 293.2 371.4 423.2 499.8 1805.8 6097
close(x)