[R] Failing to print mer object in an RData image

[Robert Zimbardo]

> Have you load lme4 before you print the object?
Yes, I have.

> If yes, it may be caused by the change of representation of "mer" class.
That may be so (although the image was saved on 12/19/2008, i.e. AFTER
the release data of the lmer version I have now. But maybe I did that
on a different computer. Question though: does that mean that the mer
object is now inaccessible and the only way to get the data back is to
run the analyses again? The changes are not backward compatible??

Thx,
RZ


>
>
> 2009/4/23 Robert Zimbardo <robertzimbardo at gmail.com>:
>> Hi all
>>
>> I have problems in accessing a mer object called model.01 from a
>> workspace that was created with R 2.8.1 and saved with save into an
>> .RData file (on Windows XP or Ubuntu 8.10, don't remember anymore).
>> Now I want to open it in R 2.9.0 on Ubuntu 8.10. I use
>>
>> # load workspace
>> load("name.RData")
>>
>> which seems to work:
>>
>> ls() # all objects in there
>> [1] "all"          "all.dd"       "model.01"     "model.sorter"
>>
>> It also recognizes the class of model.01:
>>
>>> class(model.01)
>> [1] "mer"
>> attr(,"package")
>> [1] "lme4"
>>
>> But when I want to print it or look at its structure:
>>
>> print(model.01)
>> Error in slot(value, what) :
>>  no slot of name "Xst" for this object of class "mer"
>>
>>> str(model.01)
>> Error in FUN(c("env", "nlmodel", "frame", "call", "flist", "X", "Xst",  :
>>  no slot of name "Xst" for this object of class "mer"
>>
>> Any idea what to do?
>>
>>> R.version
>> platform       i486-pc-linux-gnu
>> arch           i486
>> os             linux-gnu
>> system         i486, linux-gnu
>> status
>> major          2
>> minor          9.0
>> year           2009
>> month          04
>> day            17
>> svn rev        48333
>> language       R
>> version.string R version 2.9.0 (2009-04-17)
>>
>>> library(help=lme4)
>> Package:       lme4
>> Version:       0.999375-28
>> Date:          2008-12-13
>>
>> Thanks,
>> RZ

> --
> HUANG Ronggui, Wincent
> PhD Candidate
> Dept of Public and Social Administration
> City University of Hong Kong
> Home page: http://asrr.r-forge.r-project.org/rghuang.html