survfit class of functions
to represent a fitted survival curve. Objects of this class have methods for the functions print,
summary, plot, points and lines. The
print.survfit method does more computation than is typical
for a print method and is documented on a separate page.
strata statement -- there is a matrix of curves and 2 subscripts may
be used.
(In this case summary.survfit will also print the data as a matrix).survfit, plot.survfit,
summary.survfit, print.survfit.