R help - Dec 2011 - Calculate survival function for AFT model

I have fit an accelerated failure time model using coxph, and have what seems
to be a simple question that I can't figure out.  

Given a vector of predictor values X, the survival time S[t|X] is the
probability the entity will survive longer than some time t.  Now, how do I
calculate this for a specific value of t?  


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Le vendredi 30 d?cembre 2011 ? 12:46 -0800, thebennjammin a ?crit
:
> I have fit an accelerated failure time model using coxph, and have what
seems
> to be a simple question that I can't figure out.  
Please specify the exact package, functions and actual code you use.
coxph(), as the name says, runs a Cox *proportional hazards* model,
which is different from an accelerated failure time model. You should
use survreg (package survival) if you want to run the later family.
> Given a vector of predictor values X, the survival time S[t|X] is the
> probability the entity will survive longer than some time t.  Now, how do I
> calculate this for a specific value of t?  
Package rms offers convenience functions to compute and plot this. See
psm() and predict.psm().


Regards