title: Get predictions from coxph
body: <pre><code># Create the simplest test data set 
  test1 &lt;- list(time=c(4,3,1,1,2,2,3), 
                status=c(1,1,1,0,1,1,0), 
                x=c(0,2,1,1,1,0,0), 
                sex=c(0,0,0,0,1,1,1)) 
  # Fit a stratified model 
  m=coxph(Surv(time, status) ~ x + sex, test1) 
  
  y=predict(m,type="survival",by="sex")
  </code></pre>
  
  <p>Basically what I am doing is making fake data called test1, then I am fitting a simple coxph model and saving it as 'm'. Then what I aim to do is get the predicted probabilities and confidence bands for the survival probability separate for sexes. My hopeful dataset 'y' will include: age, survival probability, lower confidence band, upper confidence band, and sex which equals to '0' or '1'.</p>