on 12/05/2008 09:10 PM Ritwik Sinha wrote: > Hi All, > > Please pardon me if I am missing something obvious here. How do I get > the Kaplan-Meier estimate function that is created by survfit and > plotted by the code. > > fit <- survfit(Surv(time, status) , data=aml) > plot(fit) > > That is, I need a function that will give me the survival estimate at > a given time: \hat{S}(t). > > Thanks in advance. > > Ritwik Sinha
See: library(survival) ?summary.survfit and note the 'times' argument. fit <- survfit(Surv(time, status) , data = aml) > summary(fit) Call: survfit(formula = Surv(time, status), data = aml) time n.risk n.event survival std.err lower 95% CI upper 95% CI 5 23 2 0.9130 0.0588 0.8049 1.000 8 21 2 0.8261 0.0790 0.6848 0.996 9 19 1 0.7826 0.0860 0.6310 0.971 12 18 1 0.7391 0.0916 0.5798 0.942 13 17 1 0.6957 0.0959 0.5309 0.912 18 14 1 0.6460 0.1011 0.4753 0.878 23 13 2 0.5466 0.1073 0.3721 0.803 27 11 1 0.4969 0.1084 0.3240 0.762 30 9 1 0.4417 0.1095 0.2717 0.718 31 8 1 0.3865 0.1089 0.2225 0.671 33 7 1 0.3313 0.1064 0.1765 0.622 34 6 1 0.2761 0.1020 0.1338 0.569 43 5 1 0.2208 0.0954 0.0947 0.515 45 4 1 0.1656 0.0860 0.0598 0.458 48 2 1 0.0828 0.0727 0.0148 0.462 > summary(fit, times = seq(0, 48, 6)) Call: survfit(formula = Surv(time, status), data = aml) time n.risk n.event survival std.err lower 95% CI upper 95% CI 0 23 0 1.0000 0.0000 1.0000 1.000 6 21 2 0.9130 0.0588 0.8049 1.000 12 18 4 0.7391 0.0916 0.5798 0.942 18 14 2 0.6460 0.1011 0.4753 0.878 24 11 2 0.5466 0.1073 0.3721 0.803 30 9 2 0.4417 0.1095 0.2717 0.718 36 5 3 0.2761 0.1020 0.1338 0.569 42 5 0 0.2761 0.1020 0.1338 0.569 48 2 3 0.0828 0.0727 0.0148 0.462 HTH, Marc Schwartz ______________________________________________ R-help@r-project.org mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide http://www.R-project.org/posting-guide.html and provide commented, minimal, self-contained, reproducible code.