flexurba (version 0.2.3)

get_adjacent: Identify adjacent cells

Description

The function identifies all cells that are adjacent to non-NA cells in x. The implementation of the function relies on the function terra::adjacent().

Usage

get_adjacent(
  x,
  cells = "all",
  adjacent_value = 1,
  include = TRUE,
  directions = 8
)

Value

SpatRaster with adjacent cells

Arguments

x

SpatRaster

cells

character / integer. Either "all" or a specific cell value. If cells="all", adjacent cells are identified for all non-NA cells in x. Otherwise, adjacent cells are only identified for cells in x with the specific cell value.

adjacent_value

integer. Value assigned to adjacent cells in the resulting grid

include

logical. Whether to include the focal cells in the resulting grid

directions

integer. Which cells are considered adjacent: 4 for rooks case (horizontal and vertical neighbours) or 8 for queens case (horizontal, vertical and diagonal neighbours)

Examples

set.seed(10)
nr <- nc <- 10
r <- terra::rast(
  ncols = nc, nrows = nr,
  ext = c(0, nc, 0, nr),
  vals = sample(c(NA, 1, 2), nr * nc, replace = TRUE, prob = c(0.8, 0.1, 0.1))
)
terra::plot(r)
adj1 <- get_adjacent(r)
terra::plot(adj1)
adj2 <- get_adjacent(r, cells = 1, include = FALSE)
terra::plot(adj2)