randomise_voronoi: Randomise locations of points based on Voronoi tesselation

In ku-awdc/HexScape: Aggregation of Spatial Data into Discrete Patches using Simple Features

Randomise locations of points based on Voronoi tesselation

Description

Randomise locations of points based on Voronoi tesselation

Usage

randomise_voronoi(
  points,
  map,
  randomise_size = 5L,
  from_type = "point",
  to_type = "centroid",
  mask_landscape = FALSE,
  additional_info = FALSE,
  sample_probs = 10^-seq_len(3L),
  max_tries = 3L,
  verbose = 1L
)

Arguments

points	the points to randomise
map	a landscape to use for masking
randomise_size	the pool size for randomisation
from_type	the basis on which to determine distance between "from" and "to" points: one of voronoi, point or centroid
to_type	the basis on which to determine distance between "from" and "to" points: one of voronoi, point or centroid
mask_landscape	should the Voronoi cells be masked using the map before distances are calculated? Has no effect for from_type=to_type="point"
additional_info	option to provide additional columns in the dataframe returned
max_tries	the maximum number of tries before failure
verbose	a positive integer determining how much progress output should be displayed (0=silent)
sample_size	the number of random points to generate within each Voronoi cell

Value

The return value depends on the input points: if the input is an sfc object and additional_info==FALSE, then the output is also an sfc object; if the input is an sf data frame, then the output is also an sf data frame with the random points in the active geometry (which will have the same name as the input); the output is always an sf data frame if additional_info==TRUE, with the randomised points as the active geometry (this will be named geometry if the input is an sfc object, or have the same name as the active geometry in the input if this was an sf data frame)

Examples

xrange <- c(0, 10)
yrange <- c(0, 10)
corners <- tribble(~x, ~y,
                   xrange[1], yrange[1],
                   xrange[2], yrange[1],
                   xrange[2], yrange[2],
                   xrange[1], yrange[2],
                   xrange[1], yrange[1]
)
library("sf")
map <- st_sfc(st_multipolygon(list(list(as.matrix(corners)))))
points <- st_sfc(lapply(1:10, function(x) st_point(runif(2,0,10))))
random <- randomise_voronoi(points, map, additional_info=TRUE)
ggplot(random) +
  geom_sf(aes(geometry=VoronoiCell)) +
  geom_sf(aes(geometry=VoronoiMasked), alpha=0.5) +
  geom_sf(aes(geometry=RandomShift)) +
  geom_sf(aes(geometry=RandomPoint)) +
  theme_void()

ku-awdc/HexScape documentation built on Jan. 10, 2025, 5:24 p.m.