Hello, May i know whether it is possible to generate data twice from?Weibull distribution?and use one as the start time and the? other as the end time, below is my code. Any suggestion on how to estimate the parameters of Weibull distribution with interval data will be highly appreciated. Thank you shape=2;scale=4;rr=5000 for(i in 1:rr){ x<-rweibull(50,shape,scale) y=rweibull(50,shape,scale) w=Surv(y,x,type="interval2") } w Chris Guure Researcher? Institute for Mathematical Research UPM