library(survival)
# READ DATA
testdata=read.table("https://folk.ntnu.no/bo/STK4080/nelson-aalen-hand.txt",header=T)
#
# KAPLAN-MEIER ESTIMATOR
#
fitKM=survfit(Surv(Time,Status)~1, data=testdata,conf.type="log-log")
summary(fitKM)
plot(fitKM)
#
#NELSON-AALEN ESTIMATOR
#
fitNA=survfit(coxph(Surv(Time,Status)~1, data=testdata))
plot(fitNA, fun="cumhaz",xlab="Time", ylab="Cumulative hazard")