simm.levy: Simulates a Levy Walk In adehabitat: Analysis of Habitat Selection by Animals

Description

This function simulates a Levy walk

Usage

 ```1 2``` ```simm.levy(date = 1:500, mu = 2, l0 = 1, x0 = c(0, 0), id = "A1", burst = id, typeII = TRUE) ```

Arguments

 `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)`.

Details

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))))`

Value

an object of class `ltraj`

Author(s)

Clement Calenge [email protected]

References

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`
 ```1 2 3 4 5 6 7``` ```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) ```