smam (version 0.2-2)

fitMovRes: Fit a Moving-Resting Model with Embedded Brownian Motion

Description

Fit a Moving-Resting Model with Embedded Brownian Motion with animal movement data at discretely observation times by maximizing a composite likelihood constructed from the marginal density of increment.

Usage

fitMovRes(data, start, method = "Nelder-Mead", optim.control = list())
cllk.m1(theta, data)

Arguments

data

a data.frame whose first column is the observation time, and other columns are location coordinates.

start

starting value of the model, a vector of three component, which represents two rate parameters of moving and resting duration, and one volatility parameter for the Brownian motion.

method

the method argument to feed optim.

optim.control

a list of control that if passed down to optim.

theta

a parameter vector of three components (similar to start)

Value

fitMovRes returns a list of the following components:

estimate

the esimated parameter vector

cloglik

composite loglikelihood evaluated at the estimate

convergence

convergence code from optim

cllk.m1 returns the composite loglikelihood constructed from the marginal distribution of each increment.

References

Yan, J., Chen, Y., Lawrence-Apfel, K., Ortega, I. M., Pozdnyakoc, V., Williams, S., and Meyer, T. (2013+) A moving-resting process with an embedded Brownian motion for animal movements. Population Ecology. Forthcoming.

Examples

tgrid <- seq(0, 10, length=2001)
## make it irregularly spaced
tgrid <- sort(sample(tgrid, 1000))
set.seed(123)
dat <- rMovRes(tgrid, 1, 1, 1, "m")
## Not run: 
# fit <- fitMovRes(dat, start=c(2, 2, 2))
# fit
# ## End(Not run)