[R] How do I specify a partially completed survival analysis model?

[Marc Schwartz]

On Nov 23, 2009, at 12:50 PM, David Winsemius wrote:

>
> On Nov 20, 2009, at 1:27 PM, David Winsemius wrote:
>
>>
>> On Nov 20, 2009, at 11:07 AM, RWilliam wrote:
>>
>>>
>>> In reply to suggestion by David W., setting an offset parameter  
>>> doesn't seem
>>> to work as R is not recognizing the "X2" part of  coxph(
>>> Surv(Time,Censor)~X1, offset=log(4.3*X2), data= a ). Also, here's  
>>> some
>>> sample data:
>>>
>>
>> The problem, arising as a result of not having a dataset against  
>> which to test my memories of syntactic niceties, is that glm and  
>> coxph use different methods of supplying offsets.
>
> It's been pointed out to me that coxph()'s required syntactic  
> incorporation of offsets is the same as glm()'s preferred inclusion  
> in the formula, and that my erroneous impression that a separate  
> offset argument is necessary might have be the result of "SAS  
> poisoning".
>
> I suspect that "infection" is the more correct biomedical analogy,  
> since I copied my use from another who was probably the index case.  
> That usage was also similar to the separate specification of offsets  
> (e.g.  $CAL LPY=%LOG(PY) $OFFSET LPY) in GLIM which was my  
> statistical upbringing.



Would that be SAS1N1 and is there a vaccine that one can distribute to  
universities and corporations to prevent the spread of the infection?

;-)

Regards,

Marc Schwartz