olmm
.Various parameters that control aspects for olmm
.
olmm_control(fit = c("nlminb", "ucminf", "optim"),
doFit = TRUE, numGrad = FALSE,
numHess = numGrad, nGHQ = 7L,
start = NULL, restricted = NULL, verbose = FALSE, ...)
A list of class olmm_control
containing
the control parameters.
character string. The name of the function to be used for the
optimization. Can be one of "nlminb"
, "ucminf"
, "optim"
logical scalar. When FALSE
an unfitted
olmm
object is returned.
logical scalar indicating whether the score function should be retrieved numerically.
logical scalar. Indicates whether the Hess matrix for
the variance-covariance matrix should be estimated numerically,
which is an approximation of the observed Fisher information. Must
be TRUE
if numGrad
is TRUE
. See details.
a positive integer specifying the number of quadrature points for the approximation of the marginal Likelihood by numerical integration.
a named numeric vector of initial values for the parameters. The parameter must be named in exactly in the way as they appear when the model is fitted.
a character vector of names of coefficients to be restricted to the initial values. The argument is ignored in case of adjacent category models.
logical scalar. If TRUE
verbose output is
generated during the optimization of the parameter estimates.
further arguments to be passed to fit
.
Reto Burgin
Initial values may decrease the computation time and avoid
divergence. The start
argument accepts a vector with named
elements according to the column names of the
model.matrix
. At the time being, initial values for
adjacent-categories models must be transformed into the
baseline-category model form.
Notice that an additional argument control
, e.g.,
control = list(trace = 1)
, can be passed access control
parameters of the optimizers. For arguments, see
ucminf
, nlminb
or
optim
.
olmm