[R] function 'vcov' for coxph in R 2.0.0

[Lei Liu]

Hi there,

After I fitted a cox model, I used vcov to obtain the 
variance of the parameter estimate. It worked correctly in 
R 1.9.1. But it failed in R 2.0.0 and the error message is 

Error in vcov(cox.1) : no applicable method for "vcov"

I don't know if it is a bug or there is some update on 
this function. Thanks!

Lei Liu
Assistant Professor
Division of Biostatistics and Epidemiology
Dept. of Health Evaluation Sciences
School of Medicine
University of Virginia

3181 Hospital West Complex
Charlottesville, VA 22908-0717

1-434-982-3364 (o)
1-734-730-1395 (c)

liulei at virginia.edu
ll9f at virginia.edu