search for: eventbefore2c

Displaying 1 result from an estimated 1 matches for "eventbefore2c".

2005 Jul 18
1
Survival dummy variables and some questions
...though, hey why not categorize the variables (I realize some folks object to categorization but the paper I am replicating appears to have done so ...) and 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;...