dear all
Can you please throw some light on this .I am getting som error when I use library(survival) model <- survreg(Surv(time, status) ~ rx + cluster(litter), rats) Error in rowsum.default(resid(fit, "dfbeta"), cluster) : 'x' must be numeric Why does it throw up error ? Thanks and Regards Sayan Dasgupta [[alternative HTML version deleted]] ______________________________________________ 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.