Use regularized Cox proportional hazard models to identify linear combinations of input variables while fitting an orsf model.
Arguments
- alpha
(double) The elastic net mixing parameter. A value of 1 gives the lasso penalty, and a value of 0 gives the ridge penalty. If multiple values of alpha are given, then a penalized model is fit using each alpha value prior to splitting a node.
- df_target
(integer) Preferred number of variables used in a linear combination.
- ...
Further arguments passed to or from other methods (not currently used).
Value
an object of class 'orsf_control'
, which should be used as
an input for the control
argument of orsf.
Details
df_target
has to be less than mtry
, which is a separate argument in
orsf that indicates the number of variables chosen at random prior to
finding a linear combination of those variables.
References
Simon, Noah, Friedman, Jerome, Hastie, Trevor, Tibshirani, Rob (2011). "Regularization paths for Cox's proportional hazards model via coordinate descent." Journal of statistical software, 39(5), 1.
See also
linear combination control functions
orsf_control_cph()
,
orsf_control_custom()
,
orsf_control_fast()
,
orsf_control()