pdf("ex0901.pdf")

ex0901dat <- read.fwf("http://www.stat.ufl.edu/~winner/data/biostat/ex0901.dat", width=c(8,8,8), 
 col.names=c("regimen", "time", "censor"))

ex0901 <- data.frame(ex0901dat)

attach(ex0901)

# Load the survival analysis package  

library(survival)

# Print out the survival times, censored values have a "+" next to them (Surv must be spelled exactly this way)

Surv(time, censor==0)

# Obtain survival tables and curves by regimen

surv.byreg <- survfit(Surv(time, censor==0)~regimen)

summary(surv.byreg)

plot(surv.byreg)

# Conduct the Log-Rank test to compare survival curves

survdiff(Surv(time,censor==0)~regimen)

dev.off()