adjacent | R Documentation |
Identify cells that are adjacent to a set of raster cells. Or identify adjacent polygons
## S4 method for signature 'SpatRaster'
adjacent(x, cells, directions="rook", pairs=FALSE, include=FALSE, symmetrical=FALSE)
## S4 method for signature 'SpatVector'
adjacent(x, type="rook", pairs=TRUE, symmetrical=FALSE)
x |
SpatRaster |
cells |
vector of cell numbers for which adjacent cells should be found. Cell numbers start with 1 in the upper-left corner and increase from left to right and from top to bottom |
directions |
character or matrix to indicated the directions in which cells are considered connected. The following character values are allowed: "rook" or "4" for the horizontal and vertical neighbors; "bishop" to get the diagonal neighbors; "queen" or "8" to get the vertical, horizontal and diagonal neighbors; or "16" for knight and one-cell queen move neighbors. If |
pairs |
logical. If |
include |
logical. Should the focal cells be included in the result? |
type |
character. One of "rook", "queen", "touches", or "intersects". "queen" and "touches" are synonyms. "rook" exclude polygons that touch at a single node only. "intersects" includes polygons that touch or overlap |
symmetrical |
logical. If |
matrix
When using global lon/lat rasters, adjacent cells at the other side of the date-line are included.
relate
, nearby
r <- rast(nrows=10, ncols=10)
adjacent(r, cells=c(1, 5, 55), directions="queen")
r <- rast(nrows=10, ncols=10, crs="+proj=utm +zone=1 +datum=WGS84")
adjacent(r, cells=11, directions="rook")
#same as
rk <- matrix(c(0,1,0,1,0,1,0,1,0), 3, 3)
adjacent(r, cells=11, directions=rk)
## note that with global lat/lon data the E and W connect
r <- rast(nrows=10, ncols=10, crs="+proj=longlat +datum=WGS84")
adjacent(r, cells=11, directions="rook")
f <- system.file("ex/lux.shp", package="terra")
v <- vect(f)
a <- adjacent(v, symmetrical=TRUE)
head(a)
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