Create a matrix showing which planning units are spatially adjacent to each other. Note that this also include planning units that overlap with each other too.
adjacency_matrix(x, ...) # S3 method for Raster adjacency_matrix(x, directions = 4L, ...) # S3 method for SpatialPolygons adjacency_matrix(x, ...) # S3 method for SpatialLines adjacency_matrix(x, ...) # S3 method for SpatialPoints adjacency_matrix(x, ...) # S3 method for sf adjacency_matrix(x, ...) # S3 method for default adjacency_matrix(x, ...)
x 


...  not used. 
directions 

dsCMatrix
sparse symmetric matrix.
Each row and column represents a planning unit.
Cells values indicate if different planning units are
adjacent to each other or not (using ones and zeros).
To reduce computational burden, cells among the matrix diagonal are
set to zero. Furthermore, if the argument to x
is a
Raster
object, then cells with NA
values are set to zero too.
Spatial processing is completed using
sf::st_intersects()
for Spatial
and
sf::sf()
objects,
and raster::adjacent()
for Raster
objects.
In earlier versions (< 5.0.0), this function was named as the
connected_matrix
function. It has been renamed to be consistent
with other spatial association matrix functions.
# load data data(sim_pu_raster, sim_pu_sf, sim_pu_lines) # create adjacency matrix using raster data ## crop raster to 9 cells r < crop(sim_pu_raster, c(0, 0.3, 0, 0.3)) ## make adjacency matrix am_raster < adjacency_matrix(r) # create adjacency matrix using polygons (sf) data ## subset 9 polygons ply < sim_pu_sf[c(1:2, 10:12, 20:22), ] ## make adjacency matrix am_ply < adjacency_matrix(ply) # create adjacency matrix using lines (Spatial) data ## subset 9 lines lns < sim_pu_lines[c(1:2, 10:12, 20:22), ] ## make adjacency matrix am_lns < adjacency_matrix(lns) # plot data and the adjacency matrices # \dontrun{ par(mfrow = c(4,2)) ## plot raster and adjacency matrix plot(r, main = "raster", axes = FALSE, box = FALSE) plot(raster(as.matrix(am_raster)), main = "adjacency matrix", axes = FALSE, box = FALSE) ## plot polygons (sf) and adjacency matrix plot(r, main = "polygons (sf)", axes = FALSE, box = FALSE) plot(raster(as.matrix(am_ply)), main = "adjacency matrix", axes = FALSE, box = FALSE) ## plot lines (Spatial) and adjacency matrix plot(r, main = "lines (Spatial)", axes = FALSE, box = FALSE) plot(raster(as.matrix(am_lns)), main = "adjacency matrix", axes = FALSE, box = FALSE) # }