Hello, i'm tring to use a cox's model for a survival analysis. I have a dataset, this is a part:
VOD SESSO fonte_sct donor RT_CGY STATOBMT TEMPO morto 1 0 F mid related 1200 CP 65 1 2 0 M mid 1200 2RC 5281 0 3 0 M mid unrelated 1200 1RC 218 0 4 0 M per unrelated 1200 2RC 484 0 5 0 F mid 1200 1RC 302 1 6 0 M mid related 1200 1RC 1235 0 but when i try this command i have a warning: > fit = coxph( Surv(TEMPO,morto==1)~ VOD + SESSO + fonte_sct + donor + RT_CGY + STATOBMT) Warning message: In coxph(Surv(TEMPO, morto == 1) ~ VOD + SESSO + fonte_sct + donor + : X matrix deemed to be singular; variable 10 14 15 18 20 21 22 24 25 26 why??? anyone know the solution of this?? Thanks Michele [[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.