stplanr (version 0.1.4)

toptail: Clip the first and last n metres of SpatialLines

Description

Takes lines and removes the start and end point, to a distance determined by the user.

Usage

toptail(l, toptail_dist, ...)

Arguments

l

A SpatialLines object

toptail_dist

The distance (in metres) to top and tail the line by. Can either be a single value or a vector of the same length as the SpatialLines object.

...

Arguments passed to rgeos::gBuffer()

Details

Note: toptailgs is around 10 times faster, but only works on data with geographic CRS's due to its reliance on the geosphere package.

Examples

data("routes_fast")
sp::proj4string(routes_fast) <- CRS("+init=epsg:4326")
r_toptail <- toptail(routes_fast, toptail_dist = 300)
plot(routes_fast, lwd = 3)
plot(r_toptail, col = "red", add = TRUE)
plot(cents, col = "blue", add = TRUE, pch = 15)
# Note the behaviour when the buffer size removes lines
r_toptail <- toptail(routes_fast, toptail_dist = 1000)
length(r_toptail) # note short routes have been removed
length(routes_fast)
plot(routes_fast, lwd = 3)
plot(r_toptail, col = "red", add = TRUE)