crwN2ll {crawl}R Documentation

-2 * log-likelihood for CTCRW models

Description

This function is designed for primary use within the crwMLE model fitting function. But, it can be accessed for advanced R and crawl users. Uses the state-space parameterization and Kalman filter method presented in Johnson et al. (2008).

Usage

crwN2ll(theta, fixPar, y, x, loctype, delta, a1.y, a1.x, P1.x, P1.y,
        lonAdj, mov.mf, err.mfX, err.mfY, stop.mf, n.errX, n.errY,
        n.mov, stopMod, driftMod)

Arguments

theta parameter values.
fixPar values of parameters held fixed (contains NA for theta values).
y latitude locations.
x longitude loations.
loctype vector with 1 or observed location, else 0.
delta time difference to next location.
a1.y initial state value for latitude.
a1.x initial state value for longitude.
P1.x intial state covariance matrix for latitude.
P1.y inital state covariance matrix for longitude.
lonAdj = 1/cos(y*pi/180) as described in Johnson et al. (2008) for polar coords. = 1 for non-polar coords.
mov.mf Movement covariate data.
err.mfX longitude error covariate data.
err.mfY latitude error covariate data.
stop.mf stopping covariate.
n.errX number or longitude error parameters.
n.errY number of latitude error parameters.
n.mov number or movement parameters.
stopMod Logical. indicates wheteher a stop model is specified.
driftMod Logical. inicates whether a drift model is specified.

Details

This function calls compiled Fortran code which can be viewed in the src directory of the crawl library.

Value

-2 * log-likelihood value for specified CTCRW model.

Author(s)

Devin S. Johnson

References

Johnson, D., J. London, M. -A. Lea, and J. Durban. 2008. Continuous-time model for animal telemetry data. Ecology 89:1208-1215.

See Also

crwMLE


[Package crawl version 1.0-3 Index]