Class

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)

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

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

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

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
#> Warning: GDAL support is provided by the sf and terra packages among others
image(x[])
#> Warning: GDAL support is provided by the sf and terra packages among others
image(as(x, "SpatialGridDataFrame"))
#> Warning: GDAL support is provided by the sf and terra packages among others

summary(as(x, "SpatialGridDataFrame"))
#> Warning: GDAL support is provided by the sf and terra packages among others
#> 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"))
#> Warning: GDAL support is provided by the sf and terra packages among others

# select first 50 rows:
summary(x[1:50])
#> Warning: GDAL support is provided by the sf and terra packages among others
#> 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])
#> Warning: GDAL support is provided by the sf and terra packages among others
#> 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])
#> Warning: GDAL support is provided by the sf and terra packages among others
#> 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])
#> Warning: GDAL support is provided by the sf and terra packages among others
#> 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]])
#> Warning: GDAL support is provided by the sf and terra packages among others
#>    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)

Class "SpatialGDAL"