How to segment or split a spatial line in R

I think the below is a solution:

library(raster)
# create some lines
cds1 <- rbind(c(-180,-20), c(-140,55), c(10, 0), c(-140,-60))
cds2 <- rbind(c(-10,0), c(140,60), c(160,0), c(140,-55))
cds3 <- rbind(c(-125,0), c(0,60), c(40,5), c(15,-45))
lns <- SpatialLines(list(Lines(list(Line(cds1)), "1"),
     Lines(list(Line(cds2)), "2"), Lines(list(Line(cds3)), "3") ))


# get coordinates
xy <- as.data.frame(lns, xy=TRUE)

# get midpoints
x <- xy$x[-1] + (xy$x[-nrow(xy)] - xy$x[-1]) / 2
y <- xy$y[-1] + (xy$y[-nrow(xy)] - xy$y[-1]) / 2
m <- cbind(x,y)

# remove mid-points between non-segments
i <- xy$cump[-1] == xy$cump[-nrow(xy)]
m <- m[i,]

plot(lns)
points(m)


On Thu, Oct 23, 2014 at 8:56 AM, Edzer Pebesma
<edzer.pebesma at uni-muenster.de> wrote:

sp::spsample also offers regular sampling of points on SpatialLines objects.

On 10/23/2014 05:21 PM, Mathieu Basille wrote:

May be a little bit far fetched, but maybe check 'redisltraj' from the
adehabitatLT package (and section 4.2.2 of the vignette [1]). Note that
it was intended for animal trajectories so might be a little bit out of
scope for you.

Mathieu.


[1]
http://cran.r-project.org/web/packages/adehabitatLT/vignettes/adehabitatLT.pdf


Le 23/10/2014 10:10, Manuel Sp?nola a ?crit :

Dear list members,

How to segment or split a spatial line in shorter equal segments, and
also,
how to get the mid point of ecah segment.

Best,

Manuel

--
Edzer Pebesma,  Co-Editor-in-Chief Computers & Geosciences
Institute for Geoinformatics (ifgi), University of M?nster
Heisenbergstra?e 2, 48149 M?nster, Germany. Phone: +49 251
83 33081 http://ifgi.uni-muenster.de GPG key ID 0xAC227795