raster (version 1.9-19)

adjacent: Adjacent cells

Description

Identify cells that are adjacent to a set of cells on a raster. See adjacency for an alternative implementation.

Usage

adjacent(x, cells, directions=4, pairs=TRUE, target)

Arguments

x

Raster* object

cells

vector of cell numbers for which adjacent cells should be found

directions

the number of directions in which cells should be connected: 4 (rook's case), 8 (queen's case), 16, or 'bishop'

pairs

Boolean. If TRUE, a matrix of pairs of adjacent cells is returned. If FAlSE, a vector of cells adjacent to from is returned (perhaps intersected with to)

target

Optional. Vector of target cell numbers that should be considered. All other adjacent cells are ignored

Value

• matrix or vector with adjacent cells.

Details

Cell numbers start with 1 in the upper-left corner and increase from left to right and from top to bottom.

See Also

adjacency

Examples

r <- raster(nrows=10, ncols=10)
adjacent(r, cells = c(1,55,100), directions=4, pairs=FALSE)