[R] Nelson-Aalen estimator in R

[Peter Dalgaard]

"Wu, Tongtong" <TTWu at mednet.ucla.edu> writes:

> I am taking a survival class.  Recently I need to do the Nelson-Aalen
> estimtor in R.  I searched through the R help manual and internet, but could
> not find such a R function.  I tried another way by calculating the
> Kaplan-Meier estimator and take -log(S).  However, the function only
> provides the summary of KM estimator but no estimated values.  Could you
> please help me with this?  I would highly appreciate your great help!

It's the log of the Fleming-Harrington estimator that equals
Nelson-Aalen. However, the main thing is that the survival package is
peculiar in that it does such transformations as part of
plot.survfit(). 

If you want the actual values of the N-A estimator, I don't think
there's any other way besides extracting the survival curve values from
the survfit object and taking logs. 

So: you should study the help pages for plot.survfit and
survfit.object.

-- 
   O__  ---- Peter Dalgaard             Blegdamsvej 3  
  c/ /'_ --- Dept. of Biostatistics     2200 Cph. N   
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