findborderquads {CTFS} | R Documentation |
Identified neighboring quadrates from a given quadrate number,
refered to as the index
. Returns the quadrat numbers within a given distance.
findborderquads(index, dist = 20, gridsize = 20, plotdim = c(1000, 500))
index |
quadrate number, between 0 and 1249 in the standard plot |
dist |
distance in m within which the neighboring quadrates are located. Distance is measured from any side of the index quadrate. |
gridsize |
side of the square quadrate, 20 x 20m by default |
plotdim |
dimensions of the plot: east-west 1000m and north-south 500m |
A quadrate is considered a neighbor if
any part of it lies within dist
of the center of the quadrate
indicated by index
. At the minimum the quadrates that share
edges, including corners, will always be returned. This is 8
quadrates. The index
quadrate is NOT returned. All values
>=0 and <20 give the same 8 quadrates for a centrally located
quadrate.
As dist
increases, more quadrates can be included up to the
edges of the plot. For gridsize
=20, 8 quadrates are
neighbors up to dist
<20. This doesn't change until
dist
>= 20, then there are 24 neighbors, etc.
This function depends upon index.to.rowcol
to identify
the neighboring quadrates.
Returns a vector of numbers, the quadrate indices for all surrounding quadrates.
Rick Condit
## Not run: sort(findborderquads(231,dist=10)) sort(findborderquads(231,dist=20)) sort(findborderquads(231,dist=0)) ## End(Not run)