lme4

  1. J

    lme in R - how do I get differences in mean values?

    Hi, my data structure is as follows: Participants experienced 8 different situations and answered the same questionnaire about their experience in each situation (the questionnaire comprises 8 dimensions, e.g. "positivity"). I wanted to assess how they experienced each situation. Now I want to...
  2. A

    Mixed model for time trend in R package lme4

    Hello! I would very much appreciate if anyone could help with my model in lme4. I have a dataset with 100 persons, specified by ID. Each of them was assessed at three time points, indicated by Time, for a specific measurement, called Score. I want to look at each person's trajectory over...
  3. C

    Two way repeated measures with zeros, non integer values, and non-normal distribution

    I would really appreciate some help with a few models I am trying to run. Essentially my data looks at how often a subject was visited depending on treatment and subject type across two years. The data looks like this: Year | Subject | SubjectType | Treatment | BlockNum | NumberOfVisits |...
  4. C

    Profile Confidence Interval in lmer model .

    When I fit lmer model with my data , there is no warning message. But when I tried to construct confidence interval by `confint` , it shows the following warning message : Warning messages: 1: In FUN(X[[i]], ...) : non-monotonic profile 2: In nextpar(mat, cc, i, delta, lowcut...
  5. C

    How can I calculate Standard Errors of Variance Estimates .

    I want to extract the "standard error" of variance component from the output of "lmer" . In Chapter 12 , Experiments with Random Factors , of the book Design and Analysis of Experiments, written by Douglas C. Montgomery , at the end of the chapter , Example 12-2 is done by SAS . In Example...
  6. C

    Standard Error of variance component from the output of lmer .

    I want to extract the "standard error" of variance component from the output of "lmer" . library(lme4) model <- lmer(Reaction ~ Days + (1|Subject), sleepstudy) The following produces estimates of variance component : s2 <- VarCorr(model)$Subject[1] It is **NOT**...
  7. M

    lme model with 3 categorical and 3 continuous variables - output coefficients?

    Hi, I have a regression model with: 3 continuous variables 3 categorical variables - taxon= 4 levels --> I get 3 coefficients in the MLM output (OK) - continent= 5 levels --> I get 4 coefficients in the MLM output (OK) - land cover= 2 levels --> I get both 2 coefficients in the MLM...
  8. K

    Multilevel meta-analysis in R using lme4 and lmer

    Dear users, I am running multilevel meta-analyses in R using lme4 and lmer. lmer(effect size ~ -1 + Covariate + (1|StudyID), data = data, weights = weights) My question is – is there a way to calculate confidence intervals that takes into account the fact that some effects are nested...
  9. trinker

    Understanding multilevel modeling

    I'm trying to learn a bit more about multilevel modeling so I'm going to start this thread here and post questions about the process as I know there are several regulars here who use multilevel models frequently. I know the nmle package exists but I'm mostly trying to figure out how lme4 works...
  10. A

    Fitting of a linea mixed model

    Hello I'm trying to modelize the diving depth of birds according to categorical (sex, age class: adults/subadults) and conitnuous parameters (temperature, salinity). The frequecy distribution of this data looks like this: many many many dives between 0-50m deep, some between 50-100m deep and...
  11. D

    Model not running when using lme4 - "Error: unexpected symbol..." message returned

    Hi all, I have been attempting to run the following model in the lme4 package in R. mod1<-glmer(perc~treatment+region+stage+treatment*stage+region*stage+(tub+aquarium), weights=no start, family=binomial, data=data) But continue to receive the following error message: >...