[R] Estimating survival?

[Min-Han Tan]

Hi,

Sorry to trouble the list. I have a problem which I'm not sure how to resolve.

I have a Cox model with 1 independent variable with 2 categories (and
thus 2 survival curves on plotting survfit)

How can I get an estimate of survival for each category at a
particular time point, with standard error?
 
Looking through ?cph and ?coxph, I'm not quite sure how to go about
that. I would really appreciate any direction here.

Thanks a million!

Min-Han