| survcondense {survival} | R Documentation |
Shorten a (time1, time2) survival dataset
Description
Counting process data sets can sometimes grow to an uweildy size, this can be used to reduce the number of rows.
Usage
survcondense(formula, data, subset, weights, na.action= na.pass, id,
start = "tstart", end = "tstop", event = "event")
Arguments
formula |
a formula object, with the response on the left of a |
data |
a data.frame in which to interpret the variables named in
the |
subset |
optional subset expression to apply to the data set |
weights |
optional variable name for case weights |
na.action |
optional removal of missing values |
id |
variable name that identifies subjects |
start |
optional character string, giving the name of the start time variable in the result |
end |
optional character string, giving the name of the stop time variable in the result |
event |
optional character string, giving the name of the event variable in the result |
Details
Through the use of the survSplit and tmerge functions, a
counting process data set will gain more and more rows of data.
Occassionally it is useful to collapse this surplus back down, e.g.,
when interest is to be focused on only a few covariates, or for
debugging. The right hand side of formula will often have only
a few variables in this use case.
If a row of data is censored, and represents the same covariates and identifier as the row below it, then the two rows can be merged together using a single (time1, time2) interval. The compression can sometimes be large.
The start, stop and end options are only used when the
left hand side of the formula has expressions that are not a simple
name, e.g. Surv(time1, time2, death | progression) would be a
case where event is used to set the outcome variable's name.
Value
a data frame
Author(s)
Terry Therneau
See Also
Examples
dim(aml)
test1 <- survSplit(Surv(time, status) ~ ., data=aml,
cut=c(10, 20, 30), id="newid")
dim(test1)
# remove the added rows
test2 <- survcondense(Surv(tstart, time, status) ~ x, test1, id=newid)
dim(test2)