Hi, I wanted to do the cox model using a matrix. The following lines illustrate what I want to do: -------------------------------- dat <- matrix(rnorm(30), ncol=3,dimnames = list(1:10,letters[1:3])) Survival <- rexp(10) Status <- ifelse(runif(10) < .7, 1, 0) mat <- as.data.frame(cbind(dat,Survival,Status))
cmod <- coxph(Surv(Survival, Status) ~ a+b+c, mat) --------------------------------- This works fine. However, I need to change the code so that the column headers ( a+b+c )are passed into the coxph function on the fly. What string/object do I need to generate so the function works? I am trying: # For example chead <- "a+b+c" cmod <- coxph(Surv(Survival, Status) ~ chead, mat) but this gives an error since I'm passing in a string. Can I change chead to something so that the code works? many thanks. [[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.