[R] Weibull survival modeling with covariate

[sms13+@pitt.edu]

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?
wieb<-survreg(Surv(labdata$time, 
labadata$censor)~labdata$cov, 
dist="weibull")

This returns:
> weib
Call:
survreg(formula = Surv(labdata$time, 
labdata$censor) ~ labdata$cov,
    dist = "weibull")

Coefficients:
(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 
covariate?

Thank you,
Steven

---------------------------------------
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Steven Shechter
PhD Candidate in Industrial Engineering
University of Pittsburgh
www.pitt.edu/~sms13