coincident {SpatialTools} | R Documentation |
Determine coincident coordinates
Description
coincident
takes the coordinate matrices
coords1
and coords2
and returns the indices
of the coincident coordinates of the two matrices.
Usage
coincident(coords1, coords2)
Arguments
coords1 |
An |
coords2 |
An |
Details
This function calls a compiled C++
program created
using the Rcpp package. This (may) result in a significant
speedup over pure R code since the search algorithm
involves loops. We assume that there are no duplicate
coordinates in coords1
and coords2
,
respectively. In other words, each row of coords1
is
unique and each row of coords2
is unique. There is
at most 1 row of coords1
that will match with a row
in coords2
.
Value
Returns a matrix with the indices of the coincident
locations. Specifically, an r \times 2
matrix will be
returned, with r
being the number of coordinates in
coords1
coinciding with coordinates in
coords2
. If row i
of the matrix is c(2, 5),
then the i
th set of coincident locations is between
the 2nd row of coords1
and the 5th row of
coords2
. If there are no coincident locations, then
a matrix of size 0 \times 2
is returned.
Author(s)
Joshua French
Examples
#Generate two sets of coordinates
loc1 <- as.matrix(expand.grid(seq(0, 1, len = 25), seq(0, 1, len = 25)))
loc2 <- as.matrix(expand.grid(seq(0, 1, len = 101), seq(0, 1, len = 101)))
coincident(loc1, loc2)