[R] AFT model time-dependent with weibull distribution

[David Winsemius]

On Aug 4, 2012, at 10:45 AM, hafida wrote:

> Dear R-community,
>>
>> I have tried to estimate an EXPONENTIEL accelerated failure time(AFT)
>> power rule model  with time-independent . For that purpose, I have  
>> used
>> the eha package.
>> Please, consider this example:
>
>  vi      Ti
> 1  26    5.79
> 2  26 1579.52
> 3  26 2323.70
snipped
> 74 38    1.13
> 75 38    0.09
> 76 38    2.38
>> aftexp<-aftreg(Surv(time,status) ~ vi,  data=data.frame(dataexp),
>> dist="exponentiel")
> Error in Surv(time, status) : Time variable is not numeric

Your variables being given to the `Surv` function do not match those  
in you data object.

>
>> aftexp<-aftreg(Surv(Ti,status) ~ vi,  data=data.frame(dataexp),
>> dist="exponentiel")
> Error in Surv(Ti, status) : object 'status' not found
>> status<- rep(1, 76)
>> status
> [1] 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1  
> 1 1 1 1
> 1 1
> [39] 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1  
> 1 1 1 1
> 1 1
>
>> cbind(dataexp, status)
>   vi      Ti status
> 1  26    5.79      1
> 2  26 1579.52      1
>
snipped
> 72 38    0.74      1
> 73 38    0.39      1
> 74 38    1.13      1
> 75 38    0.09      1
> 76 38    2.38      1
>
>> aftexp<-aftreg(Surv(Ti,status) ~ vi,  data=data.frame(dataexp),
>> dist="exponentiel")
> Error in aftreg.fit(X, Y, dist, strats, offset, init, shape, id,  
> control,  :
>  exponentiel is not an implemented distribution

You are spelling 'exponential' incorrectly (in English anyway.)

Bon chance;
David.
>
>> aftexp<-aftreg(Surv(time,status) ~ vi,  data=data.frame(dataexp),
>> dist="exponentiel")
> Error in Surv(time, status) : Time variable is not numeric
>> pleas help me to find a solution to my problem
>
>
-- 

David Winsemius, MD
Alameda, CA, USA