[R] Class "coef.mer" into a data.frame?

[Jukka Koskela]

Thank you! This was exactly what I was looking for.

Jukka

Lainaus "David Winsemius" <dwinsemius at comcast.net>:

>
> On Dec 31, 2010, at 2:49 AM, Jukka Koskela wrote:
>
>> Hello,
>>
>> Could somebody please tell me what am I doing wrong in following?
>>
>> I try extract coefficients (using arm-package) from the lmer  
>> frunction, but I get the
>> following warning:
>> a<-data.frame(coef(res))
>> Error in as.data.frame.default(x[[i]], optional = TRUE,  
>> stringsAsFactors = stringsAsFactors) :
>> cannot coerce class "coef.mer" into a data.fram
>>
>> I think I have done it before the same way and it has worked, but  
>> not any more..
>
> Are you sure you were not looking at just one particular element of  
> a coef.mer object?
>
>> fm1 <- lmer(Reaction ~ Days + (Days|Subject), sleepstudy)
>
>> a<-data.frame(coef(fm1))
> Error in as.data.frame.default(x[[i]], optional = TRUE,  
> stringsAsFactors = stringsAsFactors) :
>   cannot coerce class '"coef.mer"' into a data.frame
>> coef(fm1)
> $Subject
>     (Intercept)       Days
> 308    253.6623 19.6665383
> 309    211.0067  1.8461362
> 310    212.4446  5.0170766
> 330    275.0971  5.6535771
> <snipped>
> .
> .
>
>> a<-data.frame(coef(fm1)[[1]])
>> a
>     X.Intercept.       Days
> 308     253.6623 19.6665383
> 309     211.0067  1.8461362
> 310     212.4446  5.0170766
> 330     275.0971  5.6535771
> 331     273.6664  7.3980095
> <snipped>
>
> -- 
>
> David Winsemius, MD
> West Hartford, CT
>
>
>