olmm-control {vcrpart} | R Documentation |
Control parameters for olmm
.
Description
Various parameters that control aspects for olmm
.
Usage
olmm_control(fit = c("nlminb", "ucminf", "optim"),
doFit = TRUE, numGrad = FALSE,
numHess = numGrad, nGHQ = 7L,
start = NULL, restricted = NULL, verbose = FALSE, ...)
Arguments
fit |
character string. The name of the function to be used for the
optimization. Can be one of |
doFit |
logical scalar. When |
numGrad |
logical scalar indicating whether the score function should be retrieved numerically. |
numHess |
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 |
nGHQ |
a positive integer specifying the number of quadrature points for the approximation of the marginal Likelihood by numerical integration. |
start |
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. |
restricted |
a character vector of names of coefficients to be restricted to the initial values. The argument is ignored in case of adjacent category models. |
verbose |
logical scalar. If |
... |
further arguments to be passed to |
Details
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
.
Value
A list of class olmm_control
containing
the control parameters.
Author(s)
Reto Burgin
See Also
Examples
olmm_control(doFit = FALSE)