R help - Feb 2007 - bootcov and cph error

Hi all,
I am trying to get bootstrap resampled estimates of covariates in a Cox
model using cph (Design library).

Using the following I get the error:
> ddist2.abr <- datadist(data2.abr)
> options(datadist='ddist2.abr') 
> cph1.abr <- cph(Surv(strt3.abr,loc3.abr)~cov.a.abr+cov.b.abr,
data=data2.abr, x=T, y=T) 
> boot.cph1 <- bootcov(cph1.abr, B=100, coef.reps=TRUE, pr=T)
1 Error in oosl(f, matxv(X, cof), Y) : not implemented for cph
models
>
Removing coef.reps argument works fine, but I really need the
coefficients if at all possible. I cant find anything in the help files
suggesting that I cant use coef.reps in a cph model. Any help
appreciated.

Cheers

Scott

_____________________________

 

Dr. Scott Williams MD

Peter MacCallum Cancer Centre

Melbourne, Australia

scott.williams at petermac.org

Williams Scott wrote:
> Hi all,
> I am trying to get bootstrap resampled estimates of covariates in a Cox
> model using cph (Design library).
> 
> Using the following I get the error:
> 
>> ddist2.abr <- datadist(data2.abr)
>> options(datadist='ddist2.abr') 
>> cph1.abr <- cph(Surv(strt3.abr,loc3.abr)~cov.a.abr+cov.b.abr,
> data=data2.abr, x=T, y=T) 
>> boot.cph1 <- bootcov(cph1.abr, B=100, coef.reps=TRUE, pr=T)
> 1 Error in oosl(f, matxv(X, cof), Y) : not implemented for cph models
> 
> Removing coef.reps argument works fine, but I really need the
> coefficients if at all possible. I cant find anything in the help files
> suggesting that I cant use coef.reps in a cph model. Any help
> appreciated.
> 
> Cheers
> 
> Scott
Sorry it's taken so long to get to this.  The documentation needs to be 
clarified.  Add loglik=FALSE to allow coef.reps=TRUE to work for cph models.

Frank
> 
> _____________________________
> 
>  
> 
> Dr. Scott Williams MD
> 
> Peter MacCallum Cancer Centre
> 
> Melbourne, Australia
> 
> scott.williams at petermac.org

-- 
Frank E Harrell Jr   Professor and Chair           School of Medicine
                      Department of Biostatistics   Vanderbilt University