make palr example

[mdsumner]

' @examples

' #library(trip)

' #library(adehabitatLT)

' #tr <- as.data.frame(as.trip(albatross))

' #trs <- split(tr, tr$id)

' #palfun <- mk_timePal(tr$date, colorRampPalette(c("red", "blue")))

' #plot(tr$x, tr$y, pch = ".")

' #for (i in seq_along(trs)) {

' # for (j in seq(nrow(trs[[i]]))[-1]) {

' # lines(trs[[i]][(j-1):j, c("x", "y")], col = palfun(trs[[i]]$date[j]))

' # }

' #}