library(survival)

Xtime = c(.6,.8,2.1,3.2,3.3,4.4,8.6)
Xcens = c(0,1,1,1,0,1,1)

#PARAMETRIC INFERENCE WITH SURVREG

data = Surv(Xtime,Xcens)

# Exponential
expfit = survreg(data ~ 1, dist="exponential")
plot(survfit(data ~ 1),main= "R(t) Empirical-exponential")
# R(t)
curve(1-pexp(x,rate =exp(-(summary(expfit)$table[,1]))), add= TRUE)

# Weibull
weibfit = survreg(data ~ 1, dist="weibull")
plot(survfit(data ~ 1),main= "R(t) Empirical-Weibull")
# R(t)
curve(1-pweibull(x,shape = 1/weibfit$scale , scale =exp(weibfit$coefficients)),add= TRUE)