Add code for #482

R/line_segment.R

@@ -0,0 +1,26 @@
+#' Divide sf LINESTRING objects into regular segments
+#' @inheritParams line2df
+#' @param n_segments The number of segments to divide the line into
+#' @param segment_length The approximate length of segments in the output (overides n_segments if set)
+#' @family lines
+#' @export
+#' @examples
+#' l <- routes_fast_sf[2, ]
+#' l_seg2 <- line_segment(l = l, n_segments = 2)
+#' plot(sf::st_geometry(l_seg2), col = 1:2, lwd = 5)
+line_segment_sf <- function(l, n_segments, segment_length = NA) {
+  if (!is.na(segment_length)) {
+    l_length <- line_length(l)
+    n_segments <- round(l_length / segment_length)
+  }
+  # browser() # tests
+  # first_linestring = lwgeom::st_linesubstring(x = l, from = 0, to = 0.2)
+  from_to_sequence = seq(from = 0, to = 1, length.out = n_segments + 1)
+  line_segment_list = lapply(seq(n_segments), function(i)
+    lwgeom::st_linesubstring(
+      x = l,
+      from = from_to_sequence[i],
+      to = from_to_sequence[i + 1])
+  )
+  do.call(rbind, line_segment_list)
+}