R help - Oct 2008 - question on lmList

Hi list,

Using the lmList function from ?nlme package? I get the following error message:

?Error in !unlist(lapply(sum.lst, is.null)) : invalid argument type?

#  this is the syntax used
#  fm_cream <-lmList(MULTDV~TIME|cod, data=zz, na.action=na.omit)
#  summary(fm_cream)

When I generate a simple example the function works, but on the real data I get
that message. I imagine that it is a common message when data is misused, but I
don?t know where the problem could be. Has anyone encountered this message and
what does it mean exactly? Is there a ?guide? or something more detailed about
the general error messages from different packages, somewhere?

Thank you very much and have a great day ahead!

Eugen Pircalabelu

eugen pircalabelu <eugen_pircalabelu <at> yahoo.com> writes:
> Using the lmList function from ?nlme package? I get the following error 
>> message: 
> 
> ?Error in !unlist(lapply(sum.lst, is.null)) : invalid argument type?
> 
try str(zz) to check if your data are strange. And plot the data, maybe there is
something funny in the data set. Also try traceback() after the error occurred,
this could give you a hint what's wrong.

Dieter