Here is a reproducible example for the Bug that both Sebastian and Dale Barr found.
As Brian mentioned in an another thread, the problem is in the interaction of Namespaces and S4 generics and which S4 generic should keep which methods. We know there are workarounds, but till now they seem either ugly or very much against the idea that conceptually there should be only one generic which may have methods defined in many different packages / namespaces. I would like us (R-core, mostly) to resolve this as quickly as possible. ------------------------------------------------------------------------- ### Do this in a fresh R session: summary # S3 generic find("summary") # base library(stats4) summary # S4 generic find("summary") # stats4 , base library(lme4) ## -> loads Matrix (and lattice) find("summary") # lme4, Matrix, stats4 , base --- 4 times ! --- fm1 <- lmer(Reaction ~ Days + (Days|Subject), sleepstudy) ## --> ## Error in lmer(Reaction ~ Days + (Days | Subject), sleepstudy) : ## cannot get a slot ("Dim") from an object of type "NULL" ------------------------------------------------------------------------- Martin Maechler >>>>> "BDR" == Prof Brian Ripley <[EMAIL PROTECTED]> >>>>> on Thu, 28 Jun 2007 06:08:45 +0100 (BST) writes: BDR> See the thread starting BDR> https://stat.ethz.ch/pipermail/r-devel/2007-June/046157.html BDR> https://stat.ethz.ch/pipermail/r-devel/2007-June/046160.html BDR> I can't reproduce this without knowing what is in your BDR> startup files: it should work with --vanilla, so please BDR> try that and try to eliminate whatever is in your BDR> .Rprofile etc that is causing the problem. BDR> Incidentally, using rcompletion is counterproductive in BDR> R 2.5.1 RC: the base functionality using rcompgen is a BDR> more sophisticated version. BDR> On Wed, 27 Jun 2007, Sebastian P. Luque wrote: >> Hi, >> >> I've begun to use the lme4 package, rather than nlme, for more flexibility >> during modelling, and running the examples in lmer I receive this error >> message: >> >> ---<---------------cut here---------------start-------------->--- R> (fm1 <- lmer(Reaction ~ Days + (Days|Subject), sleepstudy)) >> Error in printMer(object) : no slot of name "status" for this object of class "table" >> R> sessionInfo() >> R version 2.5.1 RC (2007-06-25 r42057) >> x86_64-pc-linux-gnu >> >> locale: >> LC_CTYPE=en_CA.UTF-8;LC_NUMERIC=C;LC_TIME=en_CA.UTF-8;LC_COLLATE=en_CA.UTF-8;LC_MONETARY=en_CA.UTF-8;LC_MESSAGES=en_CA.UTF-8;LC_PAPER=en_CA.UTF-8;LC_NAME=C;LC_ADDRESS=C;LC_TELEPHONE=C;LC_MEASUREMENT=en_CA.UTF-8;LC_IDENTIFICATION=C >> >> attached base packages: >> [1] "stats4" "stats" "graphics" "grDevices" "utils" "datasets" >> [7] "methods" "base" >> >> other attached packages: >> lme4 Matrix rcompletion rcompgen lattice diveMove >> "0.99875-2" "0.99875-2" "0.1-2" "0.1-13" "0.15-11" "0.7-9" >> reshape >> "0.7.4" >> ---<---------------cut here---------------end---------------->--- >> >> Since this is happening in a fresh session, and with code from examples >> help file, this looks like a potential bug. Any thoughts? >> >> >> Cheers, ______________________________________________ R-devel@r-project.org mailing list https://stat.ethz.ch/mailman/listinfo/r-devel