Re: [R] survival::survfit,plot.survfit

2009-03-03 Thread Bernhard Reinhardt
You are right. In my case it doesn´t make much difference since the mean of my covariates is about 0. I made some more plots and again I´m confused. I thought when forcing all covariates via the newdata argument to be zero I would get the baseline function since the "linear predictor" is then

Re: [R] survival::predict.coxph

2009-02-27 Thread Bernhard Reinhardt
Hello Therry, it´s really great to receive some feedback from a "pro". I´m not sure if I´ve got the point right: You suppose that the cox-model isn´t good at forecasting an expected survival time because of the issues with the prediction of the survival-function at the right tail and one shoul

[R] survival::predict.coxph

2009-02-26 Thread Bernhard Reinhardt
Hi, I just came across another question concerning predict.coxph Terry Therneau states in "A Package for Survival Analysis in S" that term <- predict(fit, type="terms") yields predicted values for the individual components of the linear predictor X*beta My coxmodel looks like: coef

Re: [R] survival::survfit,plot.survfit

2009-02-26 Thread Bernhard Reinhardt
Jeff Xu wrote: I am confused when trying the function survfit. my question is: what does the survival curve given by plot.survfit mean? is it the survival curve with different covariates at different points? or just the baseline survival curve? for example, I run the following code and get the

[R] survival::predict.coxph

2009-02-25 Thread Bernhard Reinhardt
Hi, if I got it right then the survival-time we expect for a subject is the integral over the specific survival-function of the subject from 0 to t_max. If I have a trained cox-model and want to make a prediction of the survival-time for a new subject I could use survfit(coxmodel, newdata=new

[R] Survival-Analysis: How to get numerical values from survfit (and not just a plot)?

2009-02-17 Thread Bernhard Reinhardt
Hi! I came across R just a few days ago since I was looking for a toolbox for cox-regression. I´ve read "Cox Proportional-Hazards Regression for Survival Data Appendix to An R and S-PLUS Companion to Applied Regression" from John Fox. As described therein plotting survival-functions works wel