Thank you for your reply, it has been helpful. Do you know if the parameters estimators are MLE estimators?
One more question: In my case study I have failures that occured on different objects that have different age and length, could I use weight to find the estimates of a weibull law and so to find the probabilty of failure per unit of length for example? Thank you very much again for your help, Boris -- View this message in context: http://r.789695.n4.nabble.com/Weights-using-Survreg-tp3781803p3785931.html Sent from the R help mailing list archive at Nabble.com. ______________________________________________ R-help@r-project.org mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide http://www.R-project.org/posting-guide.html and provide commented, minimal, self-contained, reproducible code.