syn.survctree: Synthesis of survival time by classification and regression trees (CART)
Description
Generates synthetic event indicator and time to event data using
classification and regression trees (without or with bootstrap).
Usage
syn.survctree(y, yevent, x, xp, proper = FALSE, minbucket = 5, ...)
Arguments
y
a vector of length n
with original time data.
yevent
a vector of length n
with original event indicator data.
x
a matrix (n
x p
) of original covariates.
xp
a matrix (k
x p
) of synthesised covariates.
proper
for proper synthesis (proper = TRUE
) a CART
model is fitted to a bootstrapped sample of the original data.
minbucket
the minimum number of observations in
any terminal node. See ctree_control
for details. ...
additional parameters passed to ctree
. Value
A list with the following components:
- syn.time
- a vector of length
k
with synthetic time values. - syn.event
- a vector of length
k
with synthetic event indicator values.
Details
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.