survival-analysis

Cox regression in MATLAB

I know there is COXPHFIT function in MATLAB to do Cox regression, but I have problems understanding how to apply it. 1) How to compare two groups of samples with survival data in days (survdays), censoring (cens) and some predictor value (x)? The groups defined by groups logical variable. Groups have different number of samples. 2) Wh...

Cox regression - round robin validation

Hi, Is it possible to do round-robin validation with the Cox model, i.e. fit the Cox model using N-1 cases and then test the Nth case on the trained model to see what the estimated survival would be for the unknown case? I've tried Matlab (coxphfit) and R (coxphfit, survfit) but maybe I'm not fuly understanding the functions because it...