Expected Survival Curve Object
survexp.object.RdThis class of objects is returned by the survexp class of functions
to represent a fitted survival curve.
Objects of this class have methods for summary, and inherit
the print, plot, points and lines
methods from survfit.
Structure
The following components must be included in a legitimate
survexp
object.
survthe estimate of survival at time t+0. This may be a vector or a matrix.
n.riskthe number of subjects who contribute at this time.
timethe time points at which the curve has a step.
std.errthe standard error of the cumulative hazard or -log(survival).
strataif there are multiple curves, this component gives the number of elements of the
timeetc. vectors corresponding to the first curve, the second curve, and so on. The names of the elements are labels for the curves.methodthe estimation method used. One of "Ederer", "Hakulinen", or "conditional".
na.actionthe returned value from the na.action function, if any. It will be used in the printout of the curve, e.g., the number of observations deleted due to missing values.
callan image of the call that produced the object.
Subscripts
Survexp objects that contain multiple survival curves can be subscripted. This is most often used to plot a subset of the curves.
Details
In expected survival each subject from the data set is matched to a
hypothetical person from the parent population, matched on the
characteristics of the parent population.
The number at risk printed here is the number of those hypothetical
subject who are still part of the calculation.
In particular, for the Ederer method all hypotheticals are retained for
all time, so n.risk will be a constant.