[R] Mean and variance of the right-censored data

Thomas Lumley tlumley at u.washington.edu
Mon Jul 25 16:43:36 CEST 2005

On Mon, 25 Jul 2005, Petr Mandys wrote:

> Thank you!
> I'm using this:
> require(NADA)
> var_sf=survfit(Surv(a, !b))
> var_result=new("cenfit", survfit=var_sf)
> Class cenfit has methods to get mean a variance from survfit result. Is
> this correct?

NADA is designed for left censoring. I don't know if it will work for 
right censoring.

There is at least one problem that hasn't been mentioned yet.  Unless 
your largest observations are uncensored you can't compute the mean or 
variance without a parametric model.

survfit() in the survival package used to produce something it called the 
mean, but it wasn't.


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