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Guess polygon's centerline

Source: R/cnt_path_guess.R
cnt_path_guess.Rd

This function, as follows from the title, tries to guess the polygon centerline by connecting the most distant points from each other. First, it finds the point most distant from the polygon's centroid, then it searches for a second point, which is most distant from the first. The line connecting these two points will be the desired centerline.

Usage

cnt_path_guess(input, skeleton = NULL, return_geos = FALSE, ...)

Arguments

input

sf, sfc or SpatVector polygons object

skeleton

NULL (default) or cnt_skeleton() output. If NULL then polygon's skeleton would be estimated in the background using specified parameters (see inherit params below).

return_geos

FALSE (default). A logical flag that controls whether the geos_geometry should be returned.

...

Arguments passed on to cnt_skeleton

keep

numeric, proportion of points to retain (0.05-5.0; default 0.5). See Details.

method

character, either "voronoi" (default) or "straight", or just the first letter "v" or "s". See Details.

Value

An sf, sfc or SpatVector class object of a LINESTRING geometry

Examples

library(sf)
library(geos)
lake <-
  sf::st_read(
    system.file("extdata/example.gpkg", package = "centerline"),
    layer = "lake",
    quiet = TRUE
  ) |>
  geos::as_geos_geometry()
# Find lake's centerline
lake_centerline <- cnt_path_guess(input = lake, keep = 1)
# Plot
plot(lake)
plot(lake_centerline, col = "firebrick", lwd = 2, add = TRUE)