zeroinfl.control | R Documentation |
Various parameters that control fitting of zero-inflated regression models
using zeroinfl
.
zeroinfl.control(method = "BFGS", maxit = 10000, trace = FALSE,
EM = FALSE, start = NULL, ...)
method |
characters string specifying the |
maxit |
integer specifying the |
trace |
logical or integer controlling whether tracing information on
the progress of the optimization should be produced (passed to |
EM |
logical. Should starting values be estimated by the EM (expectation maximization) algorithm? See details. |
start |
an optional list with elements |
... |
arguments passed to |
All parameters in zeroinfl
are estimated by maximum likelihood
using optim
with control options set in zeroinfl.control
.
Most arguments are passed on directly to optim
, only trace
is also
used within zeroinfl
and EM
/start
control the choice
of starting values for calling optim
.
Starting values can be supplied, estimated by the EM (expectation maximization)
algorithm, or by glm.fit
(the default). Standard errors are
derived numerically using
the Hessian matrix returned by optim
. To supply starting
values, start
should be a list with elements "count"
and "zero"
and potentially "theta"
(for negative binomial components only) containing
the starting values for the coefficients of the corresponding component of the
model.
A list with the arguments specified.
Achim Zeileis <Achim.Zeileis@R-project.org>
zeroinfl
## Not run:
data("bioChemists", package = "pscl")
## default start values
fm1 <- zeroinfl(art ~ ., data = bioChemists)
## use EM algorithm for start values
fm2 <- zeroinfl(art ~ ., data = bioChemists, EM = TRUE)
## user-supplied start values
fm3 <- zeroinfl(art ~ ., data = bioChemists,
start = list(count = c(0.7, -0.2, 0.1, -0.2, 0, 0), zero = -1.7))
## End(Not run)
Add the following code to your website.
For more information on customizing the embed code, read Embedding Snippets.