crwN2ll {crawl} | R Documentation |
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).
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)
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. |
This function calls compiled Fortran code which can be viewed in the
src
directory of the crawl library.
-2 * log-likelihood value for specified CTCRW model.
Devin S. Johnson
Johnson, D., J. London, M. -A. Lea, and J. Durban. 2008. Continuous-time model for animal telemetry data. Ecology 89:1208-1215.