| simm.levy {adehabitat} | R Documentation |
This function simulates a Levy walk
simm.levy(date = 1:500, mu = 2, l0 = 1, x0 = c(0, 0),
id = "A1", burst = id, typeII = TRUE)
date |
a vector indicating the date (in seconds) at which
relocations should be simulated. This vector can be of class
POSIXct. *Note that the time lag between two relocations
should be constant* (regular trajectories required) |
mu |
The exponent of the Levy distribution |
l0 |
The minimum length of a step |
x0 |
a vector of length 2 containing the coordinates of the startpoint of the trajectory |
id |
a character string indicating the identity of the simulated
animal (see help(ltraj)) |
burst |
a character string indicating the identity of the simulated
burst (see help(ltraj)) |
typeII |
logical. Whether the simulated trajectory should be of
type II (TRUE, time recorded) or not (FALSE, time not
recorded). See help(ltraj). |
This function simulates a Levy flight with exponent mu.
This is done by sampling a random relative angle from a uniform
distribution (-pi, pi) for each step, and a step length generated by
dt * (l0 * (runif(1)^(1/(1 - mu))))
an object of class ltraj
Clément Calenge calenge@biomserv.univ-lyon1.fr
Bartumeus, F., da Luz, M.G.E., Viswanathan, G.M. Catalan, J. (2005) Animal search strategies: a quantitative random-walk analysis. Ecology, 86: 3078–3087.
chi, rwrpnorm,
simm.brown, ltraj,
simm.crw, simm.mba,
simm.levy
set.seed(411) w <- simm.levy(1:500, mu = 1.5, burst = "mu = 1.5") u <- simm.levy(1:500, mu = 2, burst = "mu = 2") v <- simm.levy(1:500, mu = 2.5, burst = "mu = 2.5") x <- simm.levy(1:500, mu = 3, burst = "mu = 3") par(mfrow=c(2,2)) lapply(list(w,u,v,x), plot, perani=FALSE)