[R] 'rms' package error

[Göran Broström]

On 04/03/2014 04:29 AM, Lucy Leigh wrote:
> Hi everyone,
> I am attempting to use the R package 'rms'
> http://biostat.mc.vanderbilt.edu/wiki/Main/Rrms
> to implement a PH weibull model, using the pphsm() function.
>
> However, I get the following error,
> f.ph <- pphsm(f)
> Warning message:
> In pphsm(f) :
>    at present, pphsm does not return the correct covariance matrix
>
> I tried simply running the example on page 117 of the manual, i.e.
> set.seed(1)
> S <- Surv(runif(100))
> x <- runif(100)
> dd <- datadist(x); options(datadist='dd')
> f <- psm(S ~ x, dist="exponential")
> summary(f) # effects on log(T) scale
> f.ph <- pphsm(f)
> ## Not run: summary(f.ph)
>
> But I still got the above error message.
> I have looked through the R help archives, and it appears that this question has been asked before in 2011, but
> there were no replies.
> http://r.789695.n4.nabble.com/HELP-td3494640.html
>
> Does anyone know how to get this function to work? Or if there is an alternative package that can implement
> a Weibull PH model?

The function 'phreg' in the package 'eha' fits parametric PH models to 
right-censored and left-truncated data for some baseline distributions, 
among them the Weibull.

Göran Broström

> Cheers,
> Lucy
>
> 	[[alternative HTML version deleted]]
>
> ______________________________________________
> R-help at r-project.org mailing list
> https://stat.ethz.ch/mailman/listinfo/r-help
> PLEASE do read the posting guide http://www.R-project.org/posting-guide.html
> and provide commented, minimal, self-contained, reproducible code.
>