similar to: testing for significance in random-effect factors using lmer

Displaying 20 results from an estimated 800 matches similar to: "testing for significance in random-effect factors using lmer"

2006 Jan 24
1
fitting generalized linear models using glmmPQL
Hi, I have tried to run the following (I know it's a huge data set but I tried to perform it with a 1 GB RAM computer): library(foreign) library(MASS) library(nlme) datos<-read.spss(file="c:\\Documents and Settings\\Administrador\\Escritorio\\datosfin.sav",to.data.frame=TRUE) str(datos) `data.frame': 1414 obs. of 5 variables: $ POB : Factor w/ 6 levels
2007 Jul 30
1
Extract random part of summary nlme
Dear helpers, I'm estimating multilevel regression models, using the lme-function from the nlme-package. Let's say that I estimated a model and stored it inside the object named 'model'. The summary of that model is shown below: Using summary(model)$tTable , I receive the following output: > summary(model)$tTable Value Std.Error DF t-value
2007 Jul 31
1
Extracting random parameters from summary lme and lmer
LS, I'm estimating multilevel regression models, using the lme-function from the nlme-package. Let's say that I estimated a model and stored it inside the object named 'model'. The summary of that model is shown below: Using summary(model)$tTable , I receive the following output: > summary(model)$tTable Value Std.Error DF t-value
2007 Jun 10
1
{nlme} Multilevel estimation heteroscedasticity
Dear All, I'm trying to model heteroscedasticity using a multilevel model. To do so, I make use of the nlme package and the weigths-parameter. Let's say that I hypothesize that the exam score of students (normexam) is influenced by their score on a standardized LR test (standLRT). Students are of course nested in "schools". These variables are contained in the
2007 Jul 30
0
Extracting random parameters from summary lme
LS, I'm estimating multilevel regression models, using the lme-function from the nlme-package. Let's say that I estimated a model and stored it inside the object named 'model'. The summary of that model is shown below: Using summary(model)$tTable , I receive the following output: > summary(model)$tTable Value Std.Error DF t-value
2003 Jul 30
2
robust regression
Hi, trying to do a robudt regression of a two-way linear model, I keep getting the following error: > lqs(obs ~ y + s -1,method="lms", contrasts=list(s=("contr.sum"))) Error: lqs failed: all the samples were singular Robust regression with M-estimators works (also regular least square fits, of course): rlm.formula(formula = obs ~ y + s - 1, method = "M",
2012 Jan 26
1
Error in ifelse(append, "a", "w") : , (list) object cannot be coerced to type 'logical'
Hello I will appreciate your help with the following. Running a script in R 2.14.1 under windows vista I get the following error message: Error in ifelse(append, "a", "w") : (list) object cannot be coerced to type 'logical' However, the very same script runs perfectly well under Ubuntu. My understanding is that this type of error is associated to
2012 May 23
1
procrustes (vegan) plot of residual differences
Hello This is a simple question but I couldn't google an answer. In the procrustes function of the vegan package, one uses plot(procrustes_object, kind=2) to obtain a plot of the residual differences. For instance: data(varespec) vare.dist <- vegdist(wisconsin(varespec)) library(MASS) mds.null <- isoMDS(vare.dist, tol=1e-7) mds.alt <- isoMDS(vare.dist,
2004 Nov 11
1
RSPerl problem with testing
Hi, I'm trying to install de RSPerl module and i have some problems trying to test it. I've tried to contact with the author but the e-mail address seems not to exist. Hope that anyone in this list could explain me a little about this problem. I have a bash shell and what i do is the following: #PERLLIB=/usr/lib/R/library/RSPerl/share/blib/arch:/usr/lib/R/library/RSPerl/share/blib/lib #
2003 Sep 20
4
persp graphs
Hi, I am doing my way on R, with much experimenting. So, I am trying to plot a 3d graphic ussing "persp" and entering a data set (attached) of UTM coordinates as x,y and a pH values as z. However when I try an error message comes out telling that increasing x and y values are expected. Jus ordering the first vector does not help, and, of course, order the first two independently
2011 Nov 21
4
Discarding a matrix based on the rowSums value
Hello I would appreciate your help on the followig. I want to generate random binary matrices but I need to discard those with all-1 rows. That is, for a 10x10 matrix with five 1's [,1] [,2] [,3] [,4] [,5] [,6] [,7] [,8] [,9] [,10] [1,] 0 0 0 0 0 0 0 0 0 1 [2,] 0 0 0 0 0 0 1 0 0 0 [3,] 0 0 0 0 0 0 1
2008 May 27
3
How to test significant differences for non-linear relationships for two locations
Hi List, I have to compare a relationship between y and x for two locations. I found logistic regression fits both datasets well, but I am not sure how to test if relationships for both sites are significantly different. I searched the r site, however no answers exactly match the question. I used Tukey's HSD to compare two means, but the relationship in my study was not simply linear. So I
2009 Sep 06
3
linear mixed model question
Hello, I wanted to fit a linear mixed model to a data that is similar in terms of design to the 'Machines' data in 'nlme' package except that each worker (with triplicates) only operates one machine. I created a subset of observations from 'Machines' data such that it looks the same as the data I wanted to fit the model with (see code below). I fitted a model in
2006 Sep 18
2
problem in font
Hi, after a debian upgrade my dev.copy2eps dont work anymore. I have this message: Error in matchFont(postscriptFonts(family)[[1]], old$encoding) : unknown font I try to change the font family in my .Rprofile: setHook(packageEvent("graphics", "onLoad"), function(...) { grDevices::ps.options(family="ComputerModern") } ) But it no fix
2002 Dec 15
2
Interpretation of hypothesis tests for mixed models
My question concerns the logic behind hypothesis tests for fixed-effect terms in models fitted with lme. Suppose the levels of Subj indicate a grouping structure (k subjects) and Trt is a two-level factor (two treatments) for which there are several (n) responses y from each treatment and subject combination. If one suspects a subject by treatment interaction, either of the following models seem
2006 Oct 18
1
lmer- why do AIC, BIC, loglik change?
Hi all, I am having issues comparing models with lmer. As an example, when I run the code below the model summaries (AIC, BIC, loglik) differ between the summary() and anova() commands. Can anyone clear up what's wrong? Thank you! Darren Ward library(lme4) data(sleepstudy) fm1<-lmer(Reaction ~ Days + (1|Subject), sleepstudy) summary(fm1) fm2<-lmer(Reaction ~ Days +
2005 Sep 25
2
summary nls output
Dear R user: I bulid a package, and in the package I use the function "nls" to solve some questions. If I have two sets of data, and I want to summary these two data's nls output, I write the command in the package source code like: { .......... summary(fm1) summary(fm2) } then i compiler the package and use "Install package(s) from local zip files" to install my
2012 Mar 20
1
Remove quotes from a string to use in a variable call
Hi, I have a string that I want to use in a variable call. How can I remove the quotes and/or the string properties of the string to use it in a variable call? Here's an example: library(lme) fm2 <- lme(distance ~ age, data = Orthodont, random = ~ 1) summary(fm2) I want to update the above regression to include new predictors according to what is in a string: predictors <-
2006 Oct 08
2
latex and anova.lme problem
Dear R-helpers, When I try > anova(txtE2.lme, txtE2.lme1) Model df AIC BIC logLik Test L.Ratio p-value txtE2.lme 1 10 8590 8638 -4285 txtE2.lme1 2 7 8591 8624 -4288 1 vs 2 6.79 0.0789 > latex(anova(txtE2.lme, txtE2.lme1)) Error: object "n.group" not found I don't even see n.group as one of the arguments of latex() I checked to see >
2012 Jan 17
1
MuMIn package, problem using model selection table from manually created list of models
The subject says it all really. Question 1. Here is some code created to illustrate my problem, can anyone spot where I'm going wrong? Question 2. The reason I'm following a manual specification of models relates to the fact that in reality I am using mgcv::gam, and I'm not aware that dredge is able to separate individual smooth terms out of say s(a,b). Hence an additional request,