Displaying 20 results from an estimated 4000 matches similar to: "Tukey on interaction means after lmer"
2008 Dec 22
0
post hoc comparisons on interaction means following lme
Dear Colleagues,
I have scoured the help files and been unable to find an answer to my
question. Please forgive me if I have missed something obvious.
I have run the following two models, where "category" has 3 levels and
"comp" has 8 levels:
mod1 <- lmer(x~category+comp+(1|id),data=impchiefsrm)
mod2 <- lmer(x~category+comp+category*comp+(1|id),data=impchiefsrm)
2008 Jul 25
1
glht after lmer with "$S4class-" and "missing model.matrix-" errors
Hello everybody.
In my case, calculating multiple comparisons (Tukey) after lmer
produced the following two errors:
> sv.mc <- glht(model.sv,linfct=mcp(comp="Tukey"))
Error in x$terms : $ operator not defined for this S4 class
Error in factor_contrasts(model) :
no 'model.matrix' method for 'model' found!
What I have done before:
> sv.growth <-
2008 Oct 16
1
lmer for two models followed by anova to compare the two models
Dear Colleagues,
I run this model:
mod1 <- lmer(x~category+subcomp+category*subcomp+(1|id),data=impchiefsrm)
obtain this summary result:
Linear mixed-effects model fit by REML
Formula: x ~ category + subcomp + category * subcomp + (1 | id)
Data: impchiefsrm
AIC BIC logLik MLdeviance REMLdeviance
4102 4670 -1954 3665 3908
Random effects:
Groups Name Variance
2018 Apr 24
0
TukeyHSD and glht differ for models with a covariate
I have a question about TukeyHSD and the glht function because I'm
getting different answers when a covariate is included in model for
ANCOVA.? I'm using the cabbages dataset in the 'MASS' package for
repeatability.? If I include HeadWt as a covariate, then I get different
answers when performing multiple comparisons using TukeyHSD and the glht
function. The difference appears
2012 Jan 12
0
glht (multicomparisons) with an interaction factor
Hi,
i was working with this model
> mq<-glm(rojos~edadysexo*zona*estacion,quasipoisson)
and i get this minimal adequate model
> anova(mq5,test="F")
Df Deviance Resid. Df Resid. Dev F Pr(>F)
NULL 518 64799
edadysexo 2 1556.5 516 63243 8.9434 0.0001524 ***
zona 4
2007 Apr 16
1
Difficulties Using glht.mmc to Calculate Tukey Intervals for Means
Greetings,
In the following one-way ANOVA I am attempting to calculate the means of
each treatment along with their 95% Tukey confidence intervals for the data
shown below using a routine from the HH package.
library(HH)
options(digits=10)
# load data
treat
voltage
1
130
1
74
1
155
1
180
2
150
2
159
2
188
2
126
3
138
3
168
3
110
3
160
4
34
2012 Jan 02
1
Is using glht with "Tukey" for lme post-hoc comparisons an appropriate substitute to TukeyHSD?
Hello,
I am trying to determine the most appropriate way to run post-hoc
comparisons on my lme model. I had originally planned to use Tukey
HSD method as I am interested in all possible comparisons between my
treatment levels. TukeyHSD, however, does not work with lme. The
only other code that I was able to find, and which also seems to be
widely used, is glht specified with Tukey:
2013 Jan 10
0
Questions about the glht function for planned comparison
Hi all,
I've posted this question before, but did not get any reply. I post it
again here and see if anybody can help. Thank you.
I have a nested model with the following effects
fixed: treatments
random: experiment_date
I used lme() to model the data
mod1 <- lme(N_cells ~treatments-1, random=~1|experiment_date, method='ML')
Then I want to compare all the other
2010 May 17
1
Query on linear mixed model
Hi R Forum
I am a newbie to R and I have been amazed by what
I can get my team to accomplish just by
implementing Scripting routines of R in all my
team's areas of interest..
Recently i have been trying to adopt R scripting
routine for some analysis with longitudanal data..
I am presenting my R script below that I have
tried to make to automate data analysis for
longitudanal data by employing
2010 Aug 06
0
Tukey post hoc test for testing interaction between two or more predictors
Hi everyone,
I woudl like to apply a Tukey post hoc after a repeated measure ANOVA. I
followed the suggestions that I found in this help -list especially
this one:
/[R] Tukey HSD (or other post hoc tests) following repeated measures ANOVA
You want to use lme() in package nlme, then glht() in the multcomp package.
This will give you multiplicity adjusted p-values and confidence intervals.
2008 Jul 25
0
glht after lmer with "$S4class-" and "missing model.matrix-" errors with DATA
maybe it's in the data? So here it comes.
> sv.growth
Grouped Data: length ~ meas | box_id
meas spec comp water box_id sprouts leaves length
long.sprout
1 1 Sv control moist 1 8.800000 37.80 211.2000
60.6
2 1 Sv xfull moist 2 7.000000 8.00 174.8000
62.8
3 1 Sv control moist 3 9.000000
2013 May 06
0
Comparaciones multiples lmer
Hola,
Lo primero muchas gracias a todos por vuesta habitual ayuda. Llevo meses
con las funciones lmer, pero tengo un problema no se como plantear unas
comparaciones multiples una vez demostrado que el factor tiene diferencias
significativas.
Tengo multiples opciones,
SoluciĆ³n A: una es hacer un bonferroni a saco (pero eso me chirria ya que
tego muchos datos)
SoluciĆ³n B: Otra es utilizar glht,
2012 Jun 13
1
Tukey Kramer with ANOVA (glm)
Hello,
I am performing a BACI analysis with ANOVA using the following glm:
fit1<-glm(log(Cucs_m+1)~(BA*Otter)+BA+Otter+ID+Primary, data=b1)
The summary(aov(fit1)) shows significance in the interaction; however, now I
would like to determine what combinations of BA and Otter are significantly
different (each factor has two levels). ID and PRIMARY substrates are
categorical and included in
2012 Jan 11
2
problems with glht for ancova
I've run an ancova, edadysexo is a factor with 3 levels,and log(lcc) is the
covariate (continous variable)
I get this results
> ancova<-aov(log(peso)~edadysexo*log(lcc))
> summary(ancova)
Df Sum Sq Mean Sq F value Pr(>F)
edadysexo 2 31.859 15.9294 803.9843 <2e-16 ***
log(lcc) 1 11.389 11.3887 574.8081 <2e-16 ***
2013 Jan 14
1
Tukey HSD plot with lines indicating (non-)significance
Dear list members,
I'm running some tests looking at differences between means for various
levels of a factor, using Tukey's HSD method.
I would like to plot the data as boxplots or dotplots, with horizontal
significance lines indicating which groups are statistically
significantly different, according to Tukey HSD. Here's a nice image
showing an example of such a graphical
2010 Nov 17
1
lme weights glht
Dear R-user
I used lme to fit a linear mixed model inlcuding weights=varPower().
Additionally I wanted to use glht to calculate Tukey-Kramer multiple
comparision.
error:
> glht(modelF, linfct=mcp(Species="Tukey"))
Error in glht.matrix(model = list(modelStruct = list(reStruct =
list(SubPlot = -0.305856275920955, :
?ncol(linfct)? is not equal to ?length(coef(model))?
>
2011 Mar 01
1
glht() used with coxph()
Hi, I am experimenting with using glht() from multcomp package together with
coxph(), and glad to find that glht() can work on coph object, for example:
> (fit<-coxph(Surv(stop, status>0)~treatment,bladder1))
coxph(formula = Surv(stop, status > 0) ~ treatment, data = bladder1)
coef exp(coef) se(coef) z p
treatmentpyridoxine -0.063 0.939 0.161
2012 Feb 27
0
Suggestion on Model Def - reg in nlme
Dear RGroup
I have a data of the type shown below:
I am trying to use lme function followed by post hoc test as given in the
code below.
Am I right in my model definition, given the problem data structure.
in the example, i have used column names of my data frame so that it is
self explanatory.
library(reshape)
library(nlme)
library(multcomp)
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
2008 Jul 31
0
multiple comparison
Dear all,
I was trying to understand how "multcomp" package works by running the
examples given in the documentation.
However I still don't understand when it comes to multiple comparison set by
user (please refer to "Ksub" in the code). Therefore I run 2 other cases
along with the original example (case 1), with the expectation I'll get the
point from the output. The