[R] Weibull survival modeling with covariate

From: <sms13+_at_pitt.edu>
Date: Thu 09 Jun 2005 - 10:39:21 EST

I was wondering if someone familiar
with survival analysis can help me with the following.
I would like to fit a Weibull curve,
that may be dependent on a covariate,
my dataframe "labdata" that has the
fields "cov", "time", and "censor". Do I do the following?

This returns:
> weib

survreg(formula = Surv(labdata$time,
labdata$censor) ~ labdata$cov,

    dist = "weibull")

(Intercept) labdata$cov
8.091955112 0.001552897

Scale= 0.7532474

Loglik(model)= -12633.6
Loglik(intercept only)= -12734.8

        Chisq= 202.41 on 1 degrees of
freedom, p= 0
n= 5496

I am not quite sure how to use the
output. I see that it gives the Scale
parameter. How do I find the Shape
paramater as a function of the

Thank you,

Steven Shechter
PhD Candidate in Industrial Engineering
University of Pittsburgh

R-help@stat.math.ethz.ch mailing list
https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide! http://www.R-project.org/posting-guide.html Received on Thu Jun 09 10:42:51 2005

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