similar to: lme: how to nest a random factor in a fixed factor?

Displaying 20 results from an estimated 10000 matches similar to: "lme: how to nest a random factor in a fixed factor?"

2008 Sep 24
0
(nlme) Repeated measures with continuous covariate in lme
Dear readers, I have a basic question about how to use lme for my design. I haven't been able to find an example in r-help that made it clear to me how to tackle this problem and unfortunately I also cannot get hold of Pinheiro & Bates 2000. I hope someone can help. Data for the response variable "foan" were collected in: · 60 plots · plots were re-sampled yearly
2008 Sep 08
1
correct lme syntax for this problem?
Hello all, I am about to send off a manuscript and, although I am fairly confident I have used the lme function correctly, I want to be 100% sure. Could some kind soul out there put my mind at ease? I am simply interested in whether a predictor (SPI) is related to height. However, there are five different populations, and each may differ in mean level of height as well as the relationship
2013 Nov 25
4
lmer specification for random effects: contradictory reults
Hi All, I was wondering if someone could help me to solve this issue with lmer. In order to understand the best mixed effects model to fit my data, I compared the following options according to the procedures specified in many papers (i.e. Baayen <http://www.google.it/url?sa=t&rct=j&q=&esrc=s&source=web&cd=1&ved=0CDsQFjAA
2008 Nov 15
1
Lattice: groups and no groups with panel.superpose
Dear R listers, I am trying to create a lattice plot with independent regression lines per group for each panel, plus one overall regression line per panel. I succeed in having the separate regression lines for each group per panel, but I can't figure out how to add the overall regression line over all groups. I have learnt a lot from the list, but I can't find an example for what I want
2009 Apr 01
3
How to prevent inclusion of intercept in lme with interaction
Dear friends of lme, After so many year with lme, I feel ashamed that I cannot get this to work. Maybe it's a syntax problem, but possibly a lack of understanding. We have growth curves of new dental bone that can well be modeled by a linear growth curve, for two different treatments and several subjects as random parameter. By definition, newbone is zero at t=0, so I tried to force the
2012 Oct 30
2
help with lme
Dear Madam or Sir I am writing you hoping, that you can help me with a problem concerning the output of regressions done with the function lme in R. I would need the standard deviations for intercepts and predictors, but in the output I can only find those for the intercepts. Could it be, that this is my fault? (I am just a beginner with R and multilevel modeling). I am sorry to annoy you with
2003 Apr 28
2
stepAIC/lme problem (1.7.0 only)
I can use stepAIC on an lme object in 1.6.2, but I get the following error if I try to do the same in 1.7.0: Error in lme(fixed = resp ~ cov1 + cov2, data = a, random = structure(list( : unused argument(s) (formula ...) Does anybody know why? Here's an example: library(nlme) library(MASS) a <- data.frame( resp=rnorm(250), cov1=rnorm(250), cov2=rnorm(250),
2009 Aug 20
1
nested, repeated measure lme
Dear all, Suppose I have a nested, repeated measure lme model. Which of the following formulae is correct? (assuming data are sampled from several plots in an agricultural experiment) (1) y~explanatory.variables,random=~time|block/plot/subplot/individual (2) y~explanatory.variables,random=~time|unique.ID.of.every.individual I have read that (2) is the only approach that works. But how could I
2009 Jan 03
1
how specify lme() with multiple within-subject factors?
I have some questions about the use of lme(). Below, I constructed a minimal dataset to explain what difficulties I experience: # two participants subj <- factor(c(1, 1, 1, 1, 2, 2, 2, 2)) # within-subjects factor Word Type wtype <- factor(c("nw", "w", "nw", "w", "nw", "w", "nw", "w")) # within-subjects factor
2013 May 02
1
multivariate, hierarchical model
Sorry for the last email, sent too early. I have a small data set that has a hierarchical structure. It has both temporal (year, months) and spatial (treatment code and zone code). The following explains the data: WSZ_Code the water supply zone code (1 to 8) Treatment_Code the treatment plant which supplies each water supply zone (1 to 4)
2008 Jul 30
1
Mixed effects model where nested factor is not the repeated across treatments lme???
Hi, I have searched the archives and can't quite confirm the answer to this. I appreciate your time... I have 4 treatments (fixed) and I would like to know if there is a significant difference in metal volume (metal) between the treatments. The experiment has 5 blocks (random) in each treatment and no block is repeated across treatments. Within each plot there are varying numbers of
2013 Feb 17
2
nested random factor using lme produces errors
Hi, I am running a mixed-effect model with a nested-random effect. I am interested in gut parasites in moose. I has three different type of treatment that I applied to moose which are from different "families". My response variable is gut parasites and the factors are moose families which is nested within treatment. My data is balanced. To answer this question, I used the lme function
2013 Jul 25
1
lme (weights) and glht
Dear R members, I tried to fit an lme model and to use the glht function of multcomp. However, the glht function gives me some errors when using weights=varPower(). The glht error makes sense as glht needs factor levels and the model works fine without weights=. Does anyone know a solution so I do not have to change the lme model? Thanks Sibylle --> works fine
2007 Feb 25
1
nested design in lme, need help with specifying model
Hi, I wonder if anyone can help me with specifying a right model for my analysis. I am a beginner to lme methods and though have spent already many hours studying from various books an on-line helps, I was unfortunately not able to find a solution to my problem on my own. Data structure: I studied escape behavior of three species of a prey to a predator. The prey specimens (many) were in a
2012 Jun 06
3
Sobel's test for mediation and lme4/nlme
Hello, Any advice or pointers for implementing Sobel's test for mediation in 2-level model setting? For fitting the hierarchical models, I am using "lme4" but could also revert to "nlme" since it is a relatively simple varying intercept model and they yield identical estimates. I apologize for this is an R question with an embedded statistical question. I noticed that a
2012 Jun 13
4
lme: extract result-function
Hi, mod <- lme(A ~ -1 + B+C+D+E+F+G, random = ~1 | ...) results in summary(mod)$coeff B C D E F G (Intercept) b c d e f g i Now I'm interested in the function f <- function(B,C,D,E,F,G) <- { return(i + b*B + c*C + d*D + e*E + f*F + g*G) } Is there a easier way to create such function with flexible number of coefficient, than do it by hand? thx Christof
2011 Dec 15
1
lme with nested factor and random effect
Hello all, I'm having difficulty with setting up a mixed model using lme in the nlme package. To summarize my study, I am testing for effects of ornamentation on foraging behavior of wolf spiders. I tested spiders at two different ages (penultimate vs. mature) and of two different phenotypes (one species tested lacks ornamentation throughout life [non-ornamented males] while the other
2009 Jun 01
2
Sweave:Figures from plot (LME output) not getting generated (pdf or eps)
Hi, I seem to be facing a strange problem when I use Sweave for creating a LaTeX document of the R lme() output --- The EPS and PDF figure files get created, but are empty. I have attached a reproducible example below (taken from the R lme() help example). ------------------------------------------------------------------------------------ \documentclass[a4paper,10pt]{article}
2012 Mar 14
1
lme code help
Hi guys, Got a few days left and I need to model a random effect of species on the body mass (logM) and temperature (K) slopes. This is what i've done so far that works: model1<-lme(logSSP~logM + K,random=~1|species,data=data1) model2<-lme(logSSP~logM + K,random=~K|species,data=data1) model3<-lme(logSSP~logM + K,random=~logM|species,data=data1) The one I now want is:
2009 Dec 14
2
Bug in lnme package?
Hi! Something funny happens to me in lnme. I don't know if it's a bug or not. Here's a short sketch of the problem (you could skip the introduction and just go to the models): I'm counting the number of spider webs ( = response variable) along two rivers, with a two-level treatment: free-flowing and dammed. There are three field sites (random factor) along each river, and