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Dear R-mixed-effects-modelers, I could not answer this questions with the book by Pinheiro & Bates and did not find anything appropriate in the archives, either ... We are preparing a short lecture on degrees of freedom and would like...

[snip ...] > > A side-line: Using the confint function on one of my models and > > comparing the confidence intervals with the point-estimates from the > > summary of the same model, it seems that confint reports confidence > > intervals for the estimated standard...

It is unlikely that your request will be answered faster if you post it a second time in exactly the same way ... > Suppose I have a linear mixed-effects model (from the package > nlme) with nested random effects (see below...

Hi Christoph, > Am I right in this lme implementation, when I want to investigate the > influence of the age.group, and the two conditions on the rt: > > my.lme <- lme(rt ~ age.group + angles * hands, data = > my.data, random = ~ 1...

Dear all, I do not seem to grasp how contrasts are set for ordered factors. Perhaps someone can elighten me? When I work with ordered factors, I would often like to be able to reduce the used polynomial to a...

Dear David and others interested, I am also trying to get to terms with mixed-effects models having several symultaneous outcomes. Thus, I was very pleased to see the Reference that Mareike provided (and slightly disappointed when I saw how...

Dear Mixed-Modelers, we are measuring brain activation in animals by non-invasively tracking brain hemodynamics using near-infrared light. We have measured 24 subjects (half of which are kept in either of two housing conditions) in three experimental conditions...

Gabriel, Thanks. I'm just frustrated by the inconsistencies in what I see in POSIXlt. I'm not even sure what the tzone attribute does. Here's an example that show behavior different from POSIXct. > tl <- as.POSIXlt("2001-04...

Dear all, I would like to use the biological symbols for male and female as plotting symbols in a scatterplot (ideally filled and non-filled). R does not seem to have these symbols using pch= in plot() nor are they...

Dear Mixed-modelers, I am aware that the point is not as simple as I have stated in the subject line but I hope to pique your curiosity and thus provoke some answers. I have come across this issue due...

> I am analysing data with a dependent variable of insect > counts, a fixed effect of site and two random effects, day, > which is the same set of 10 days for each site, and then > transect, which is nested within site...

Dear all, earlier this year, I started to look into how I could estimate the relative contribution of the between-subjects variability relative to several levels of (summed) within-subject variabilities in the context of mixed models. Because I am...

I have just realised that I sent this to Per only. For those interested on the list: -----Original Message----- From: Gygax Lorenz FAT Sent: Tuesday, September 14, 2004 4:35 PM To: 'Per Tor??ng' Subject: RE: [R] glmmPQL and...

Dear Thierry, many thanks for your time and input. > Your model requires a distance matrix of 2.69e11 elements (518000 * 518000). The > random effects fixes at lot of them at zero, but you still need 24 * 3 * 12 * 8 = 6912...

> So, is this analysis correct: are there hidden costs for free > software like R in the time required to learn it? At least > currently, for the people I know (biologists, ecologists, > oceanographers, ...), this is perfectly true. This is even an...

Dear Mixed-modelers, in a recently submitted paper, we used a glmm to estimate the risk of claw injuries in dairy cows on a set of 36 farms that differed in the type of flooring and were visited three times...

Dear all, Ben Bolker was kind enough to point out that in the most current (development) version of lme4 they had done some work on predict, simulate, and refit which may help my problem. Indeed, with this version, the error...

Dear Sophie, > I wonder if anyone can please offer any advice on a model > including 2 fixed effects and 1 random effect, as well as a > covariate? > > The experimental design is as follows: > I have a two by two factor...

Dear all, I am working with R Version 0.62.2 (July 10, 1998) on a SuSE Linux 5.2. I have troubles in understanding the function image (). Can someone enlighten me? I'd like to draw a square image...

I think that the issue, at least with the online calculator that I looked at, is that it does not adjust the standard deviation of the test statistic for ties, so the standard deviation is larger and hence larger p...