Dear All, I am doing a parametric survival analysis with: fit <- survreg(Surv(xyz$start, xyz$stop, xyz$event, type="interval") ~ 1, dist='loglogistic') At this point I do not want to look into covariates, hence the '~1' as model formulation. As event types I have exact, interval, and right censored lifetime data. Everything works fine. For reasons that are not important here now, I wanted to look for the effects of 'randomly' re-allocating event types to the lifetime data. However, when I did this (keeping everything else the same), R returned this error message: Error in survreg.fit(X, Y, weights, offset, init = init, controlvals control, : NA/NaN/Inf in foreign function call (arg 9) I am puzzled by this error message and can't find anything in the archives etc. Your input would be greatly appreciated. Best regards, Michael Michael Drescher Ontario Forest Research Institute Ontario Ministry of Natural Resources 1235 Queen St East Sault Ste Marie, ON, P6A 2E3 Tel: (705) 946-7406 Fax: (705) 946-2030 [[alternative HTML version deleted]]