Re: [R] Coxph with factors

From: Kylie-Anne Richards <>
Date: Sun 17 Jul 2005 - 21:27:45 EST

Thank you again for your help.

Your suggestions worked perfect. The problems I had when using f.pom=factor(-3, levels=seq(-3,2.5, by=0.5)) were a silly mistake on my part (as suspected and dually pointed out). Thanks for the notes on baseline. I was not aware of the inaccuracies when using it at z=0.

I will be back with questions on computationally efficient time dependant survival functions next month.


> On Sat, 16 Jul 2005, Thomas Lumley wrote:
>> Yes, but you don't need to go via the baseline. The survival curves for
>> any two covariate vectors z1 and z2 are related by
>> S(t; z1)= S(t; z2)^(z1-z2)
> Actually
> S(t; z1)=S(t;z2) ^(beta'(z1-z2))
> of course.
> -thomas
> mailing list PLEASE do read the posting guide! Received on Sun Jul 17 21:34:01 2005

This archive was generated by hypermail 2.1.8 : Fri 03 Mar 2006 - 03:33:46 EST