R help - Jan 2004 - estimation of lambda and gamma with std errors for a weibull model

Dear R experts,

How should lambda and gamma (with std.errors) be calculated for a weibull model
with age as an independent predictor? I have assumed that this can be done with
survreg with e. g. (summary(survreg(Surv(time, status) ~ age, dist =
'weibull')) ) and predict.survreg with e.g. (predict(model, se.fit = T, 
newdata = data.frame(age = seq(50, 80, 5)) but unfortunately I'm uncapable
to sort out how to get the lambda and gamma values (with std.errors). I
haven't found any example of this in the help pages and would really
appreciate  any help!

With best wishes and thanks in advance for any help

Fredrik Lundgren

On Wed, Jan 14, 2004 at 09:10:51PM +0100, Fredrik Lundgren
wrote:
> Dear R experts,
> 
> How should lambda and gamma (with std.errors) be calculated for a weibull
model with age as an independent predictor? I have assumed that this can be done
with survreg with e. g. (summary(survreg(Surv(time, status) ~ age, dist =
'weibull')) ) and predict.survreg with e.g. (predict(model, se.fit = T, 
newdata = data.frame(age = seq(50, 80, 5)) but unfortunately I'm uncapable
to sort out how to get the lambda and gamma values (with std.errors). I
haven't found any example of this in the help pages and would really
appreciate  any help!
In my package 'eha', function 'weibreg', you will find short
discussion of the
different parametrizations of the Weibull distribution. Weibull (in base) and
weibreg (eha) use the same parametrization, different from the one in 
survreg. See the help page for weibreg. Oops, I can spot an error in that page;
the reference to 'dgamma' should really be to 'dweibull'.

G?ran
> 
> With best wishes and thanks in advance for any help
> 
> Fredrik Lundgren
> 
> ______________________________________________
> R-help at stat.math.ethz.ch mailing list
> https://www.stat.math.ethz.ch/mailman/listinfo/r-help
> PLEASE do read the posting guide!
http://www.R-project.org/posting-guide.html
-- 
 G?ran Brostr?m                    tel: +46 90 786 5223
 Department of Statistics          fax: +46 90 786 6614
 Ume? University                   http://www.stat.umu.se/egna/gb/
 SE-90187 Ume?, Sweden             e-mail: gb at stat.umu.se