similar to: simplifying a lmer model

Displaying 20 results from an estimated 2000 matches similar to: "simplifying a lmer model"

2005 Aug 12
2
coercing created variables into a new data frame using na.omit()
Hi, I am an R newbie and one thing I am having trouble with binding variables that I have created within one data frame into a new data frame when using na.omit(). To illustrate this problem I will give the example I am working on and the approah I have been using:- data.frame1<-filepath.... attach(data.frame1) #create a new variable using a function new.variable<-rep(1,length(weight3))
2006 Aug 10
1
help with structuring random factors using lmer()
Hi, I am an R beginner and having problems structuring my REML models. I have a model with y=weight x1=time x2=timesquared id=individual identity I need to structure the model such that in the random effects there is a constant intercept for all individuals but a separate individual slope for both x1 and x2 (a coefficient score for every individual).
2006 Aug 16
1
[SPAM] - RE: REML with random slopes and random intercepts giving strange results - Bayesian Filter detected spam
Can you provide the summary(m2) results? > -----Original Message----- > From: Simon Pickett [mailto:S.Pickett at exeter.ac.uk] > Sent: Wednesday, August 16, 2006 7:14 AM > To: Doran, Harold > Cc: r-help at stat.math.ethz.ch > Subject: [SPAM] - RE: [R] REML with random slopes and random > intercepts giving strange results - Bayesian Filter detected spam > > Hi again,
2006 Aug 11
1
help:coerce lmer.coef to matrix
Hi, Thanks for your response, it nearly worked! But it only wrote one coloumn of data and not the three columns I need. Using fixef(m1) doesnt give the same results as coef(m1) when you are using more than one random effect. I need the coefficients for each individual so I use coef(m1) to get this which results in an object of class lmer.coef, 3 columns by 700 rows. as.data.frame() wont work on
2006 Aug 24
1
help: trouble using lines()
Hi R experts, I have been using ReML as follows... model<-lmer(late.growth~mtf+year+treat+hatch.day+hatch.day:year+hatch.day:treat+ mtf:treat+ treat:year+ year:treat:mtf+(1|fybrood), data = A) then I wanted to plot the results of the three way interaction using lines() as follows... tmp<-as.vector(fixef(model)) graph1<-plot(mtf,fitted(f2), xlab=list("Brood Size"),
2007 Aug 14
1
graph dimensions default
Hi, I would like to (if possible) set the default width and height for graphs at the start of each session and have each new graphic device overwrite the previous one. I only know how to do this using windows(width=,height=...) which opens up a new plotting device every time, so I end up with lots of graphs all over the place until I get the one I want! Thanks in advance, Simon Simon Pickett
2006 Aug 15
1
REML with random slopes and random intercepts giving strange results
Hi everyone, I have been using REML to derive intercepts and coeficients for each individual in a growth study. So the code is m2 <- lmer(change.wt ~ newwt+(newwt|id), data = grow) Calling coef(model.lmer) gives a matrix with this information which is what I want. However, as a test I looked at each individual on its own and used a simple linear regression to obtain the same information, then
2007 Feb 27
2
str() to extract components
Hi, I have been dabbling with str() to extract values from outputs such as lmer etc and have found it very helpful sometimes. but only seem to manage to extract the values when the output is one simple table, any more complicated and I'm stumped :-( take this example of the extracted coeficients from a lmer analysis... using str(coef(lmer(resp3~b$age+b$size+b$pcfat+(1|sex), data=b)))
2007 Apr 27
1
how to be clever with princomp?
Hi all, I have been using princomp() recently, its very useful indeed, but I have a question about how to specify the rows of data you want it to choose. I have a set of variables relating to bird characteristics and I have been using princomp to produce PC scores from these. However since I have multiple duplicate entries per individual (each bird had a varying number of chicks), I only want
2012 May 02
0
MCMCglmm priors including phylogeny
Hi all, I'm hoping I might be able to get some help with some issues specifying priors for MCMCglmm. I'm trying to fit a gaussian glmm using MCMCglmm to a data set with two (correlated) response variables. The response variables are both logit-transformed proportions (there are a few reasons why I've chosen these with gaussian error over binomal glmm, which I won't go into).
2012 Jun 26
2
MuMIn - assessing variable importance following model averaging, z-stats/p-values or CI?
Dear R users, Recent changes to the MuMIn package now means that the model averaging command (model.avg) no longer returns confidence intervals, but instead returns zvalues and corresponding pvalues for fixed effects included in models. Previously I have used this package for model selection/averaging following Greuber et al (2011) where it suggests that one should use confidence intervals from
2006 Sep 05
1
help: advice on the structuring of ReML models for analysing growth curves
Hi R experts, I am interested on the effects of two dietry compunds on the growth of chicks. Rather than extracting linear growth functions for each chick and using these in an analysis I thought using ReML might provide a neater and better way of doing this. (I have read the pdf vignette("MlmSoftRev") and "Fitting linear mixed models in R" by Douglas Bates but I am not
2006 Oct 20
1
arrows and points for error bars
Hello everyone, I have successfully made an error bar graph using the points() command with the arrows() command to maually add on the standard errors. However, one slightly annoying feature of using this method is that the points dont line up exactly with the arrows (if you look carefully the points are never perfectly in the centre of the arrow), even when you move the arrows around in an
2005 Dec 09
1
Residuals from GLMMs in the lme4 package
Hello there This is the first time I have used r-help message board so I hope I have got the right address. I am trying to check the residuals of a GLMM model(run using the package lme4). I have been able to check the residiuals of REMLs in lme4 using the following: m1<-lmer(vTotal~Week+fCollar+ (1|fCat), collars) res<-resid(m1) plot(res) qqnorm(res) library(MASS) par(mfrow=c(2,3))
2007 Apr 19
4
general question about plotting multiple regression results
Hi all, I have been bumbling around with r for years now and still havent come up with a solution for plotting reliable graphs of relationships from a linear regression. Here is an example illustrating my problem 1.I do a linear regression as follows summary(lm(n.day13~n.day1+ffemale.yell+fmale.yell+fmale.chroma,data=surv)) which gives some nice sig. results Coefficients:
2012 May 18
3
colocar subscripts y cursiva
Hola He estado tratando varias formas de colocar el subíndice para los grados de libertad del F test y la expresión adj; y sencillamente no funciona. legend("topright",legend=c(expression('r[adj]=0.40'),expression('F[3,23]=15.43'),expression('P < 0.001')),col=black, bty='n',cex=0.9) Luego al tratar de colocar las cusriva utilizando par(font=3)
2010 Feb 09
1
Missing interaction effect in binomial GLMM with lmer
Dear all, I was wondering if anyone could help solve a problem of a missing interaction effect!! I carried out a 2 x 2 factorial experiment to see if eggs from 2 different locations (Origin = 1 or 2) had different hatching success under 2 different incubation schedules (Treat = 1 or 2). Six eggs were taken from 10 females (random = Female) at each location and split between the treatments,
2012 Jun 28
3
Sobre survival analysis
Hola Estoy tratando de correr un survival analysis usando un Cox regression model. Tengo una duda respecto a la organizacion del script. Tengo una variable que es -tamano del individuo- y quiero ver si hay diferencia en sobrevivencia respecto a tamano. Como diseno de campo los tamanos fueron ubicados de forma aleatoria en bloques al azar. Cuado planteo el script tengo algo como:
2012 Jun 30
2
Significance of interaction depends on factor reference level - lmer/AIC model averaging
Dear R users, I am using lmer combined with AIC model selection and averaging (in the MuMIn package) to try and assess how isotope values (which indicate diet) vary within a population of animals. I have multiple measures from individuals (variable 'Tattoo') and multiple individuals within social groups within 4 locations (A, B, C ,D) crucially I am interested if there are
2011 Feb 23
1
Plot confidence intervals
   Hello, list:    I'm not sure about where to send this question. I have several repeatability calculations, together with their 95% confidence intervals, and I would like to plot them, in a way similar to error bars. I was wondering if there is any specific function to do this, or any method I can apply in R, as I haven't found anything like that in the R book.    Thank you very much