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Class "coef.mer" into a data.frame?

2 messages · Jukka Koskela, David Winsemius

Jukka Koskela
# 
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..

Jukka
David Winsemius
#
On Dec 31, 2010, at 2:49 AM, Jukka Koskela wrote:

            

      
      
      
    

        
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>