#  R code for the bladder cancer data

# Enter the data into a data frame.

set1 <- read.table("c:/st565/data/bladder.txt",
      header=F, col.names=c("patient", "time", 
       "status", "treat", "init", "size")) 
set1$treat <- set1$treat-1

options(contrasts=c("contr.treatment", "contr.poly"))

bfit1 <- coxph(Surv(time, status) ~ treat, 
          data = set1, x=T, y=T, robust=T,
               method="efron", singular.ok=T)
summary(bfit1)

bfit2 <- coxph(Surv(time, status) ~ treat+init+size, 
          data = set1, x=T, y=T, robust=T,
               method="efron", singular.ok=T)
summary(bfit2)