swh:1:snp:a4c99a50dc49f82b591f268001b320f8c3ca0041
Tip revision: dc000f2a5f006d137f66716b086025d618bf8306 authored by John M Chambers on 14 July 2008, 00:00:00 UTC
version 1.0-5
version 1.0-5
Tip revision: dc000f2
trackSpeed.R
trackSpeed <- function(coords, time) {
dt <- diff(as.numeric(time))
d2 <- diff(as.matrix(coords))^2
speed <- d2[,1]
ndim <- ncol(d2)
if(ndim > 1)
speed <- d2 %*% rep(1,ndim)
else
speed <- d2
sqrt(as.vector(speed))/dt
}