GSIF (version 0.5-5.1)

tile: Tiles (subsets or clips) a spatial object to regular blocks

Description

Tiles objects of class "Spatial*" or "RasterLayer*" into regular blocks.

Usage

# S4 method for SpatialPointsDataFrame
tile(x, y, block.x, …)
# S4 method for SpatialPixelsDataFrame
tile(x, y, block.x, …)
# S4 method for SpatialPolygonsDataFrame
tile(x, y, block.x, tmp.file = TRUE, 
    program, show.output.on.console = FALSE, …)
# S4 method for SpatialLinesDataFrame
tile(x, y, block.x, tmp.file = TRUE, 
    program, show.output.on.console = FALSE, …)
# S4 method for RasterLayer
tile(x, y, block.x, tmp.file = TRUE, 
    program, show.output.on.console = FALSE, …)

Arguments

x

object of class "Spatial*" "RasterLayer"

y

list of "SpatialPolygons"; if missing will be derived based on block.x

block.x

numeric; size of block in meters or corresponding mapping units

tmp.file

logical; specifies whether to generate a temporary file

program

character; location of the auxiliary program in the system

show.output.on.console

logical; specifies whether to print the progress of a function

…

optional arguments that can be passed to the getSpatialTiles

Value

Returns a list of objects of the same class as the input object.

Details

When working with objects of type "SpatialLinesDataFrame", "SpatialPolygonsDataFrame" and or "RasterLayer", the function looks for FWTools binary files ogr2ogr and warp. FWTools is a separate program and must be installed separately.

See Also

getSpatialTiles

Examples

# NOT RUN {
## spatial pixels:
library(sp)
data(meuse.grid)
gridded(meuse.grid) <- ~x+y
tl <- getSpatialTiles(meuse.grid, block.x=1000)
image(meuse.grid)
lines(as(tl, "SpatialLines"))
## all at once:
pix.lst <- tile(meuse.grid, block.x=1000)
# }
# NOT RUN {
## lines:
library(plotKML)
data(eberg_contours)
line.lst <- tile(eberg_contours, block.x=5000)
spplot(line.lst[[1]][2])
## polygons:
data(eberg_zones)
## this one requires ogr2ogr function:
pol.lst <- tile(eberg_zones, block.x=5000)
spplot(pol.lst[[1]][1])
## raster files via rgdal:
library(rgdal)
fn = system.file("pictures/SP27GTIF.TIF", 
 package = "rgdal")
obj <- GDALinfo(fn)
ras.lst <- getSpatialTiles(obj, block.x=1000)
offset <- c(ras.lst$offset.y[1], ras.lst$offset.x[1])
region.dim <- c(ras.lst$region.dim.y[1], 
  ras.lst$region.dim.x[1])
## read the first tile:
SP27GTIF_T1 <- readGDAL(fn, offset=offset, 
  region.dim=region.dim)
str(SP27GTIF_T1)
# }