Remove geographical identity

Build a buffer around a set of geographical coordinates and take a random point around the buffer. The function is used to omit the precise location of tricot participants while keeping a close distance to the trial environment.

rmGeoIdentity(longlat, dist = 0.015, nQuadSegs = 2L, seed = NULL, ...)

Arguments

longlat

a data.frame or matrix with geographical coordinates long lat

dist

numeric, buffer distance for all longlat

nQuadSegs

integer, number of segments per quadrant

seed

integer, the seed for random number generation. Leave it NULL (the default) for data that will be shared. The random displacement does not depend on the original coordinates, so anyone who knows the seed can reproduce it and recover the exact locations. Use a seed only for tests or internal reproducibility, and never publish it

...

further arguments passed to sf methods

Value

A data frame with the random coordinates long lat within the buffer

Examples

if (FALSE) { # interactive()
library("sf")

xy = matrix(c(11.097799, 60.801090,
               11.161298, 60.804199,
               11.254428, 60.822457),
             nrow = 3, ncol = 2, byrow = TRUE)

rmGeoIdentity(xy)

#' the function also handles NAs

xy2 = matrix(c(11.097799, 60.801090,
                NA, NA,
                11.161298, 60.804199,
                11.254428, 60.822457,
                11.254428, NA),
              nrow = 5, ncol = 2, byrow = TRUE)

rmGeoIdentity(xy2)
}