Generates synthetic event indicator and time to event data using classification and regression trees (without or with bootstrap).
syn.survctree(y, yevent, x, xp, proper = FALSE, minbucket = 5, ...)
a vector of length n
with original time data.
a vector of length n
with original event indicator data.
a matrix (n
x p
) of original covariates.
a matrix (k
x p
) of synthesised covariates.
for proper synthesis (proper = TRUE
) a CART
model is fitted to a bootstrapped sample of the original data.
the minimum number of observations in
any terminal node. See ctree_control
for details.
additional parameters passed to ctree
.
A list with the following components:
a vector of length k
with synthetic time values.
a vector of length k
with synthetic event indicator values.
The procedure for synthesis by a CART model is as follows:
For each xp
find the terminal node.
Randomly
draw a donor from the members of the node and take the observed
value of yevent
and y
from that draw as the
synthetic values.
NOTE that when the function is called by setting elements of method in
syn()
to "survctree"
, the parameter minbucket
can be supplied to syn()
as e.g. survctree.minbucket
.