[R] R-squared in proportional hazards regression

Hi I'm trying to interpret the output from the coxph command. One of the outputs is: Rsquare= 0.01 (max possible= 0.069 ) Given that the methods for calculating R squared and its validity with proportional hazards regression are debated in the literature - can anyone tell me exactly how this

Re: [R] Fold function with several time varying covariates

ary's Campus Norfolk Place London W2 1PG Tel: +44 (0)20 7594 3265 Email: h.jenkin...@imperial.ac.uk Website: http://www1.imperial.ac.uk/medicine/people/h.jenkins/ -Original Message- From: Allan Engelhardt [mailto:all...@cybaea.com] Sent: 29 June 2009 14:20 To: Jenkins, Helen

[R] Fold function with several time varying covariates

Hi I'm trying to use the fold function as described here: http://cran.r-project.org/doc/contrib/Fox-Companion/appendix-cox-regression.pdf Page9 It does say that you can use this when you have more than one time varying covariate: in the description of the argument cov it says: "cov: A vector gi