Hello,

I'm quite new to R and want to make a Weibull-regression with the survival package. I know how to build my "Surv"-object and how to make a standard-weibull regression with "survreg".
However, I want to fit a translated or 3-parametric weibull dist to account for a failure-free time.
I think I would need a new object in survreg.distributions, but I don't know how to create that correctly. I've tried to inherit it from the "extreme" value dist, analogous to the implemented weibull-dist like so:
survreg.distributions$weibull3p$name <- "weibull"
survreg.distributions$weibull3p$dist <- "extreme"
survreg.distributions$weibull3p$trans <- function(y, x0) log(y) + x0
survreg.distributions$weibull3p$dtrans <- function(y) 1/y
survreg.distributions$weibull3p$itrans <- function(x, x0) exp(x-x0)
I then get a failure by survregDtest(survreg.distributions$weibull3p) that x0 is missing (since the transformation function is expected to take only one argument).

Any ideas? Or is there maybe a package somewhere that supports 3-parametric weibull regression which I missed?

Regards,
Andreas


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