The control for ba()
. From gamlss.add::ba.control()
and gamlss::bam()
.
Usage
ba.control(
offset = NULL,
method = "fREML",
control = list(),
select = FALSE,
scale = 0,
gamma = 1,
knots = NULL,
sp = NULL,
min.sp = NULL,
paraPen = NULL,
chunk.size = 10000,
rho = 0,
AR.start = NULL,
discrete = TRUE,
cluster = NULL,
nthreads = 2,
gc.level = 1,
use.chol = FALSE,
samfrac = 1,
coef = NULL,
drop.unused.levels = TRUE,
drop.intercept = NULL,
...
)
Arguments
- offset
The offset in the formula.
- method
The method argument in
bam()
.- control
A list of fit control parameters to replace defaults returned by gam.control. Any control parameters not supplied stay at their default values.
- select
The
select
argument inbam()
. Determine should selection penalties be added to the smooth effects, so that they can in principle be penalized out of the model.- scale
For the scale parameter. If this is positive then it is taken as the known scale parameter. Negative signals that the scale paraemter is unknown. 0 signals that the scale parameter is 1 for Poisson and binomial and unknown otherwise.
- gamma
The
gamma
argument inbam()
. Increase above 1 to force smoother fits.- knots
The
knots
argument inbam()
. An optional list containing user specified knot values to be used for basis construction.- sp
The
sp
argument inbam()
. A vector of smoothing parameters can be provided here.- min.sp
The
min.sp
argument inbam()
. Lower bounds can be supplied for the smoothing parameters.- paraPen
The
paraPen
argument inbam()
. Optional list specifying any penalties to be applied to parametric model terms.- chunk.size
The model matrix is created in chunks of this size, rather than ever being formed whole.
- rho
An AR1 error model can be used for the residuals (based on dataframe order), of Gaussian-identity link models. This is the AR1 correlation parameter.
- AR.start
Logical variable of same length as data,
TRUE
at first observation of an independent section of AR1 correlation.- discrete
With
method="fREML"
it is possible to discretize covariates for storage and efficiency reasons. Ifdiscrete
isTRUE
, a number or a vector of numbers for each smoother term, then discretization happens. If numbers are supplied they give the number of discretization bins.- cluster
bam
can compute the computationally dominant QR decomposition in parallel using parLapply from theparallel
package, if it is supplied with a cluster on which to do this (a cluster here can be some cores of a single machine).- nthreads
Number of threads to use for non-cluster computation (e.g. combining results from cluster nodes).
- gc.level
To keep the memory footprint down, it can help to call the garbage collector often, but this takes a substatial amount of time. Setting this to zero means that garbage collection only happens when R decides it should. Setting to 2 gives frequent garbage collection. 1 is in between.
- use.chol
By default
bam
uses a very stable QR update approach to obtaining the QR decomposition of the model matrix. For well conditioned models an alternative accumulates the crossproduct of the model matrix and then finds its Choleski decomposition, at the end. This is somewhat more efficient, computationally.- samfrac
For very large sample size Generalized additive models the number of iterations needed for the model fit can be reduced by first fitting a model to a random sample of the data, and using the results to supply starting values. This initial fit is run with sloppy convergence tolerances, so is typically very low cost.
samfrac
is the sampling fraction to use. 0.1 is often reasonable.- coef
Initial values for model coefficients.
- drop.unused.levels
By default unused levels are dropped from factors before fitting. For some smooths involving factor variables you might want to turn this off.
- drop.intercept
Set to
TRUE
to force the model to really not have the a constant in the parametric model part, even with factor variables present.- ...
Other arguments.