Simulation of a Bivariate Ornstein-Uhlenbeck Process
This function simulates a bivariate Ornstein-Uhlenbeck process for animal movement.
simm.mou(date = 1:100, b = c(0, 0),
a = diag(0.5, 2), x0 = b,
sigma = diag(2), id = "A1",
burst = id, proj4string=CRS())date |
a vector indicating the date (in seconds) at which
relocations should be simulated. This vector can be of class
|
b |
a vector of length 2 containing the coordinates of the attraction point |
a |
a 2*2 matrix |
x0 |
a vector of length 2 containing the coordinates of the startpoint of the trajectory |
sigma |
a 2*2 positive definite matrix |
id |
a character string indicating the identity of the simulated
animal (see |
burst |
a character string indicating the identity of the simulated
burst (see |
proj4string |
a valid CRS object containing the projection
information (see |
The Ornstein-Uhlenbeck process can be used to take into account an "attraction point" into the animal movements (Dunn and Gipson 1977). This process can be simulated using the stochastic differential equation:
dz = a (b - z(t)) dt + Sigma dB2(t)
The vector b contains the coordinates of the attraction
point. The matrix a (2 rows and 2 columns) contains
coefficients controlling the force of the attraction. The matrix
Sigma controls the noise added to the movement (see
?simm.mba for details on this matrix).
An object of class ltraj
Clement Calenge clement.calenge@ofb.gouv.fr
Stephane Dray dray@biomserv.univ-lyon1.fr
Manuela Royer royer@biomserv.univ-lyon1.fr
Daniel Chessel chessel@biomserv.univ-lyon1.fr
Dunn, J.E., & Gipson, P.S. (1977) Analysis of radio telemetry data in studies of home range. Biometrics 33: 85–101.
suppressWarnings(RNGversion("3.5.0"))
set.seed(253)
u <- simm.mou(1:50, burst="Start at the attraction point")
v <- simm.mou(1:50, x0=c(-3,3),
burst="Start elsewhere")
w <- simm.mou(1:50, a=diag(c(0.5,0.1)), x0=c(-3,3),
burst="Variable attraction")
x <- simm.mou(1:50, a=diag(c(0.1,0.5)), x0=c(-3,7),
burst="Both")
z <- c(u,v,w,x)
plot(z, addpoints = FALSE, perani = FALSE)Please choose more modern alternatives, such as Google Chrome or Mozilla Firefox.