Connect polylines together to a single line — connect

Taking the union() of polylines doesn't connect them together, but places them in the same arrangement (it might even break them up depending on their monotonicity). connect_polylines() does exactly what it advertises. it takes a vector of polylines (or a list of polyline vectors) and combines them into a single polyline by connecting the endpoint of each polyline with the start point of the next. If the end and the start are equal the duplicate vertex will be removed.

Usage

connect_polylines(x, na.rm = TRUE)

Arguments

x: A polyclid_polyline vector or a list of these
na.rm: Should NA values be removed when connecting. If FALSE and the input contains NA, the result will be NA.

Value

A polyclid_polyline vector

Examples

sine <- polyline(
  seq(0, 2*pi, length.out = 20),
  sin(seq(0, 2*pi, length.out = 20))
)
loop <- polyline(
  c(0, 5, 6, 5, 0),
  c(-1, 1, 0, -1, 1)
)
pl <- c(sine, loop)

plot(connect_polylines(pl))


sine1 <- sine[1:10]
sine2 <- sine[10:20]

sine == connect_polylines(c(sine1, sine2))
#> [1] TRUE