On 5/14/07, Steven McKinney <[EMAIL PROTECTED]> wrote: > > Running lme4 0.9975-13 > I'm still getting the warning > > $ operator not defined for this S4 class, returning NULL in: x$symbolic.cor
It was my mistake. I fixed the problem in the development sources long ago but I haven't uploaded a new release since doing so. I'll upload a new release next week - this is finals week for us and they seem to expect that we will do things like grade exams rather than debugging code. :-) > Is there a more recent version? > Is there any known problem with this warning > (incorrect results etc.) ? Not really. It is a benign cut-and-paste error. If you want to fix it now look for the function printMer in the source file lme4/R/lmer.R and change the default for the symbolic.cor argument to FALSE. > > sessionInfo() > R version 2.5.0 (2007-04-23) > powerpc-apple-darwin8.9.1 > > locale: > C > > attached base packages: > [1] "stats" "graphics" "grDevices" "utils" "datasets" "methods" > [7] "base" > > other attached packages: > lme4 Matrix lattice > "0.9975-13" "0.9975-11" "0.15-4" > > > > Steven McKinney > > Statistician > Molecular Oncology and Breast Cancer Program > British Columbia Cancer Research Centre > > email: [EMAIL PROTECTED] > > tel: 604-675-8000 x7561 > > BCCRC > Molecular Oncology > 675 West 10th Ave, Floor 4 > Vancouver B.C. > V5Z 1L3 > Canada > > > > > -----Original Message----- > From: [EMAIL PROTECTED] on behalf of Douglas Bates > Sent: Mon 5/14/2007 12:43 PM > To: Iasonas Lamprianou > Cc: r-help@stat.math.ethz.ch > Subject: Re: [R] lmer function > > On 5/14/07, Iasonas Lamprianou <[EMAIL PROTECTED]> wrote: > > Does anyone know if the lmer function of lme4 works fine for unbalanced > > designs? I have the examination results of 1000 pupils on three subjects, > > one score every term. So, I have three scores for English (one for every > > term), three scores for maths etc. However, not everybody was examined in > > maths, not everybody was examined in English etc, but everybody was in > > effect examined on four subjects. I also have information abouit the > > school. Would this model hive the right results for the variance components? > > > > mod_3_f <- lmer(SCORE ~ GENDER + (1 |ID ) + (1 | TERM) + (1 | SUBJECT) , > > Dataset) > > > > Linear mixed-effects model fit by REML > > Formula: SCORE ~ GENDER + (1 | ID) + (1 | TERM) + (1 | SUBJECT) > > Data: Dataset > > AIC BIC logLik MLdeviance REMLdeviance > > 247882 247926 -123936 247871 247872 > > Random effects: > > Groups Name Variance Std.Dev. > > ID (Intercept) 5.97288 2.44395 > > TERM (Intercept) 5.10307 2.25900 > > SUBJECT (Intercept) 0.25943 0.50934 > > Residual 4.41673 2.10160 > > number of obs: 53978, groups: ID, 5695; TERM, 4; SUBJECT, 4 > > Fixed effects: > > Estimate Std. Error t value > > (Intercept) 14.30352 1.15870 12.34 > > GENDER[T.Male] -1.01776 0.06885 -14.78 > > Correlation of Fixed Effects: > > Warning in x$symbolic.cor : $ operator not defined for this S4 class, > > returning NULL > > What version of the lme4 package are you using? (Use sessionInfo() to > check.) I think the bug that causes that warning has been fixed in > the most recent version. > > > (Intr) > > GENDER[T.M] -0.023 > > > How do I interpert the results? > > Do you really want to treat SUBJECT as a random effect? I think it > would be more common to treat it as a fixed effect. If I understand > you correctly there are only two levels of SUBJECT and these are > repeatable levels. If that is the case one could model SUBJECT as a > fixed effect or consider its interaction within student with the term > (SUBJECT|ID). > > It would make sense to regard the pair of responses in maths and > English for each student in each term as a multivariate response but, > at present, that model cannot be fit with lmer. > > I would also question whether you want the TERM to be modeled with a > random effect. > > ______________________________________________ > R-help@stat.math.ethz.ch mailing list > https://stat.ethz.ch/mailman/listinfo/r-help > PLEASE do read the posting guide http://www.R-project.org/posting-guide.html > and provide commented, minimal, self-contained, reproducible code. > > ______________________________________________ R-help@stat.math.ethz.ch mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide http://www.R-project.org/posting-guide.html and provide commented, minimal, self-contained, reproducible code.
