lwgeom (version 0.1-0)

bounding_circle: Generate the minimum bounding circle

Description

Generate the minimum bounding circle

Usage

st_minimum_bounding_circle(x, nQuadSegs = 30)

Arguments

x

object of class sfg, sfg or sf

nQuadSegs

number of segments per quadrant (passed to st_buffer)

Value

Object of the same class as x

Details

st_minimum_bounding_circle uses the lwgeom_calculate_mbc method also used by the PostGIS command ST_MinimumBoundingCircle. It is only available if the package was linked against liblwgeom, which is currently not the case for the binary CRAN distributions; see the package source code repository for instructions how to install liblwgeom. The example below shows how to run-time check the availability of liblwgeom.

Examples

# NOT RUN {
library(sf)

x = st_multipoint(matrix(c(0,1,0,1),2,2))
y = st_multipoint(matrix(c(0,0,1,0,1,1),3,2))

mbcx = st_minimum_bounding_circle(x)
mbcy = st_minimum_bounding_circle(y)

if (.Platform$OS.type != "windows") {
  plot(mbcx, axes=TRUE); plot(x, add=TRUE)
  plot(mbcy, axes=TRUE); plot(y, add=TRUE)
}

nc = st_read(system.file("shape/nc.shp", package="sf"))
state = st_union(st_geometry(nc))

if (.Platform$OS.type != "windows") {
  plot(st_minimum_bounding_circle(state), asp=1)
  plot(state, add=TRUE)
}

# }