grid2nb | R Documentation |
The function builds a neighbours list for a grid topology. It works for a k-dimentional grid topology, k>=1.
grid2nb(grid, d = grid@cells.dim,
queen = TRUE, nb = TRUE, self = FALSE)
grid |
An object of class |
d |
A scalar (for one dimentional grid) or a length k vector specyfying the number of grid cells in each direction of the k dimentions. |
queen |
Logical. Default is TRUE. To inform if the queen neighbourhood structure should be considered. If FALSE, only a hyper-cube with a common face will be considered neighbour. If TRUE, a single shared coordinate meets the contiguity condition. |
nb |
Default TRUE. If TRUE, return the result as a neighbours
list with class |
self |
Default FALSE, to indicate if the hyper-cube neighbour itself should be considered a neighbour. |
Either a matrix, if “nb” is FALSE or a neighbours list with
class nb
. See card
for details of “nb”
objects.
This applies to a k-dimentional grid topology.
Elias T Krainski eliaskrainski@gmail.com
poly2nb
, summary.nb
,
card
nb <- grid2nb(d = c(5L, 5L, 5L))
nb
summary(nb)
if (require("sp", quietly=TRUE)) {
gt <- GridTopology(c(.125,.1), c(.25,.2), c(4L, 5L))
nb1 <- grid2nb(gt, queen = FALSE)
nb2 <- grid2nb(gt)
sg <- SpatialGrid(gt)
plot(sg, lwd=3)
plot(nb1, coordinates(sg), add=TRUE, lty=2, col=2, lwd=2)
plot(nb2, coordinates(sg), add=TRUE, lty=3, col=4)
str(grid2nb(d=5))
}
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