search for: weibullaft

Displaying 1 result from an estimated 1 matches for "weibullaft".

2011 Aug 21
3
pooled hazard model with aftreg and time-dependent variables
...I created two variables for this purpose: a variable representing individuals, as a factor, and a variable for each sample, and included them in the model. I provide an example below. If I include the factor sample the analysis works. If I include both sample + individual like this: >> weibullaft<-aftreg(Surv(sta,time,S) ~ TDC1 + TIC1 + sample + individual, >> dist="weibull", >> data.frame=Data, id=ID) , it appears an error with aftreg saying: Error in solve.default(fit$hessian) : Lapack routine dgesv: system is exactly singular With phreg the error is: f...