Message-ID: <E13BFA91-6071-4F87-8A01-AB1009CA9C0A@me.com>
Date: 2009-11-23T23:41:37Z
From: Marc Schwartz
Subject: How do I specify a partially completed survival analysis model?
In-Reply-To: <23F907C9-692D-4E62-9253-2FA34C5E872C@comcast.net>
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