Identify pairs of cells that are adjacent.

adjacencyFromTransition(x)

## Arguments

## Value

A two column matrix with each row containing
a pair of adjacent cells.

## Details

Extracts the indices of those cells that are connected
(e.g. cells i,j that have a non-zero value in the transition
matrix).

Cell numbers are unique indices of cells in the original grid.
By convention, cell numbers start with 1 in the upper-left
corner of the grid and increase from left to right and from top
to bottom.

## See also

## Examples

library("raster")
r <- raster(nrows = 6, ncols = 7,
xmn = 0, xmx = 7,
ymn = 0, ymx = 6,
crs = "+proj=utm +units=m")
r[] <- runif(6 * 7)
tr <- transition(r, function(x) 1 / mean(x), 8)
aft <- adjacencyFromTransition(tr)
head(aft)