Definition of the initial number of boosting iterations, step size and other hyper-parameters for boosting algorithms.
boost_control(mstop = 100, nu = 0.1,
risk = c("inbag", "oobag", "none"), stopintern = FALSE,
center = TRUE, trace = FALSE)
An object of class boost_control
, a list.
an integer giving the number of initial boosting iterations.
If mstop = 0
, the offset model is returned.
a double (between 0 and 1) defining the step size or shrinkage parameter.
The default is probably too large for many applications
with family = Poisson()
and a smaller value is better.
a character indicating how the empirical risk should be
computed for each boosting iteration. inbag
leads to
risks computed for the learning sample (i.e., all non-zero weights),
oobag
to risks based on the out-of-bag (all observations with
zero weights) and none
to no risk computations at all.
a logical that defines if the boosting algorithm stops internally when the out-of-bag risk in one iteration is larger than the out-of-bag risk in the iteration before. Can also be a positive number giving the risk difference that needs to be exceeded.
deprecated. A logical indicating if the numerical covariates should be mean
centered before fitting. Only implemented for
glmboost
. In blackboost
centering is not needed. In gamboost
centering is only needed if bols
base-learners are specified without intercept. In this
case centering of the covariates is essential and should be done
manually (at the moment). Will be removed in favour of
a corresponding argument in glmboost
in the future
(and gives a warning).
a logical triggering printout of status information during the fitting process.
Objects returned by this function specify hyper-parameters of the
boosting algorithms implemented in glmboost
,
gamboost
and blackboost
(via the control
argument).
mboost