Create a tiling scheme from a raster

The input may be an actual raster or a matrix. There is an assumed block size of 256x256, and the scheme will record the number of tiles in each dimension and the amount of "overlapping dangle" when the dimensions of the data don't fit neatly within the tiles.

grout(dimension, extent = NULL, blocksize = NULL, projection = NA_character_)

Arguments

dimension: number of columns and rows of the raster grid
extent: extent of the raster grid xmin,xmax,ymin,ymax
blocksize: tile dimensions in columns (X) and rows (Y)
projection: the projection (crs) of the grid

Value

A "tile scheme" object with information about the tile spacing and extent.

Details

If extent is not provided the default 'xmin=0,xmax=ncol,ymin=0,ymax=nrow' is used.

The tile scheme object has print and plot methods for basic information.

See example in the README with 'wk::rct' to generate plot-able and efficient spatial objects from the scheme.

Examples

## one block tile (too big)
grout(c(87, 61), blocksize = c(256L, 256L))
#>           tiles: 1, 1 (x * y = 1)
#>           block: 256, 256 
#>          dangle: 169, 195 
#> tile resolution: 256, 256 
#>     tile extent: 0, 256, -195, 61 (xmin,xmax,ymin,ymax)
#>           grain: 256, 256 (256 : x, 256 : y)
## more size appropriate
grout(c(87, 61), blocksize = c(8, 8))
#>           tiles: 8, 11 (x * y = 88)
#>           block: 8, 8 
#>          dangle: 1, 3 
#> tile resolution: 8, 8 
#>     tile extent: 0, 88, -3, 61 (xmin,xmax,ymin,ymax)
#>           grain: 8, 8 (8 : x, 8 : y)
grout(c(10, 20), c(0, 1, 0, 2), blocksize = c(256, 256))
#>           tiles: 1, 1 (x * y = 1)
#>           block: 256, 256 
#>          dangle: 246, 236 
#> tile resolution: 25.6, 25.6 
#>     tile extent: 0, 25.6, -23.6, 2 (xmin,xmax,ymin,ymax)
#>           grain: 25.6, 25.6 (256 : x, 256 : y)