search for: daysbefore2c

Displaying 1 result from an estimated 1 matches for "daysbefore2c".

2005 Jul 18
1
Survival dummy variables and some questions
...turn the variables into factors and then try the analysis. E.g., Dataset <- read.table("categ.dat", header=TRUE) Dataset$eventbefore2c <- factor(Dataset$eventbefore) .. other IVs here ... surv.mod1 <- coxph(Surv(start, stop, event) ~ sex2 + ageonset2c + eventbefore2c + daysbefore2c, data=Dataset) Strangely enough, I receive a warning message when the variables are treated in this way: X matrix deemed to be singular; variable 11 in: coxph(Surv(start, stop, event) ~ sex2 + ageonset2c + eventbefore2c + I don’t receive any warnings just treating the variables in their i...