flnl | R Documentation |
For a specific set of parameter values, it computes and returns the negative
log-likelihood for the distance sampling likelihood for distances that are
unbinned, binned and a mixture of both. The function flnl
is the
function minimized using optim
from within
ddf.ds
.
flnl(fpar, ddfobj, misc.options, fitting = "all")
fpar |
parameter values for detection function at which negative log-likelihood should be evaluated |
ddfobj |
distance sampling object |
misc.options |
a |
fitting |
character |
Most of the computation is in flpt.lnl
in which the negative
log-likelihood is computed for each observation. flnl
is a wrapper
that optionally outputs intermediate results and sums the individual
log-likelihood values.
flnl
is the main routine that manipulates the parameters using
getpar
to handle fitting of key, adjustment or all of the
parameters. It then calls flpt.lnl
to do the actual computation of
the likelihood. The probability density function for point counts is
fr
and for line transects is fx
.
fx
=g(x)/mu (where g(x) is the detection function); whereas,
f(r)=r*g(r)/mu where mu in both cases is the normalizing constant. Both
functions are in source code file for link{detfct}
and are called from
distpdf
and the integral calculations are made with
integratepdf
.
negative log-likelihood value at the parameter values specified in
fpar
These are internal functions used by ddf.ds
to fit
distance sampling detection functions. It is not intended for the user to
invoke these functions but they are documented here for completeness.
Jeff Laake, David L Miller
flt.var
, detfct
Add the following code to your website.
For more information on customizing the embed code, read Embedding Snippets.