Displaying 20 results from an estimated 3000 matches similar to: "post hoc comparisons on interaction means following lme"
2008 Dec 23
0
Tukey on interaction means after lmer
Dear Colleagues,
I fit this model:
mod1 <- lmer(x~category*comp+(1|id),data=impchiefsrm)
where category has 4 levels and comp has 8 levels.
These work:
glht(mod1, linfct=mcp(category="Tukey")
glht(mod1, linfct=mcp(comp="Tukey")
What I'd like is (conceptually):
glht(mod1, linfct=mcp(category:comp="Tukey")
but it gives a syntax error.
Any help is
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
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:
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 <-
2010 Jul 21
1
post hoc test for lme using glht ?
Hi,
I have a fairly simple repeated measures-type data set I've been attempting
to analyze using the lme function in the nlme package. Repeated searches
here and other places lead me to believe I have specified my model
correctly.
However, I am having trouble with post-hoc tests. From what I gather, other
people are successfully using the glht function from the multcomp package to
2010 Aug 30
1
Help With Post-hoc Testing
I am trying to do post-hoc tests associated with a repeated measures
analysis with on factor nested within respondents.
The factor (SOI) has 17 levels. The overall testing is working fine, but I
can''t seem to get the multiple comparisons to work.
The first step is to "stack" the data.
Then I used "lme" to specify and test the overall model.
Finally
2009 Oct 15
0
Two way anova repeated measures and post hoc testing - several questions
Hi,
I am fairly new to R and still trying to figure out how it all works, and I
have run into a few issues. I apologize in advance if my questions are a bit
basic, I'm also no statistics wizard, so part of my problem my be a more
fundamental lack of knowledge in the field.
I have a dataset that looks something like this:
Week Subj Group Readout
0 1 A 352.2
1 1 A
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.
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
2012 Feb 12
2
ANCOVA post-hoc test
Could you please help me on the following ANCOVA issue?
This is a part of my dataset:
sampling dist h
1 wi 200 0.8687212
2 wi 200 0.8812909
3 wi 200 0.8267464
4 wi 0 0.8554508
5 wi 0 0.9506721
6 wi 0 0.8112781
7 wi 400 0.8687212
8 wi 400 0.8414646
9 wi 400 0.7601675
10 wi 900 0.6577048
11 wi 900
2009 Aug 14
1
post hoc test after lme
Hi!
I am quiet new with R and I have some problems to perform a posthoc test
with an lme model.
My model is the following:
>lme1<-lme(eexp~meal+time, random=~1|id,na.action=na.omit)
and then i try to get a post hoc test:
>summary(glht(lme1,linfct=mcp(meal="Tukey)))
but I get a warning message: Erreur dans as.vector(x, mode) : argument
'mode' incorrect
Thank you for your
2009 Mar 22
1
Multiple Comparisons for (multicomp - glht) for glm negative binomial (glm.nb)
Hi
I have some experimental data where I have counts of the number of
insects collected to different trap types rotated through 5 different
location (variable -location), 4 different chemical attractants [A, B,
C, D] were applied to the traps (variable - semio) and all were
trialled at two different CO2 release rates [1, 2] (variable CO2) I also
have a selection of continuous variables
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
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
2013 Jul 05
1
multcomp on significant interaction in coxme model
Dear R community
I currently try to get post hoc multiple comparisons with the package
multcomp from a cox mixed-effects model, where the survival is explained
by two variables (cover with levels: nocover and cover; treatment with
levels: tx, uv, meta), whose interaction is significant.
I read Hothorn, T. 2011: Additional multcomp Examples and there is an
example involving a two-way ANOVA with
2009 Sep 26
1
Multiple comparisons for coxph survival analysis model
Hello, all R-users!
I am working on fitting a survival analysis model using the coxph
function for Cox proportional hazards regression model. Data look like
usual:
==========================
group block death censor
Group1 1 4 1
Group1 1 12 1
...
Group2 30 4 1
Group2 30 4 1
...
Group3 57 16
2012 Jun 22
0
R: Error with glht function: Error in mcp2matrix(model, linfct = linfct) : Variable(s) 'Type' have been specified in 'linfct' but cannot be found in 'model'!
Hello everybody,
problem solved, there was a typo.
I wrote Type instead of Material
Best
----Messaggio originale----
Da: angelo.arcadi@virgilio.it
Data: 22-giu-2012 11.05
A: <r-help@r-project.org>
Ogg: Error with glht function: Error in mcp2matrix(model, linfct = linfct) : Variable(s) 'Type' have been specified in 'linfct' but cannot be found in 'model'!
2007 Aug 28
0
Problem with lme using glht for multiple comparisons
Hi everyone,
I am new to R and have a question that relates to unplanned post-hoc comparisons using the multcomp package after a mixed effects model. I couldn't find the answer to it in the archive or in any manual.
I have a dataset in which several plants have been treated in a particular way and a continuous response variable has been measured depending on several leaves per plant. I am
2012 Mar 14
0
statistical contrasts on 3-way interaction
Hi all,
I was trying to use glht() from multcomp package to construct a contrast on interaction term
in a linear model to do some comparisons. I am little uncertain on how to construct contrasts on a 3-way interaction containing a continuous variable, and hope someone can confirm what I did is correct or wrong:
The linear model has a continuous dependent
variable “y”, with treatment factor
2010 Jul 07
0
interaction post hoc/ lme repeated measures
Hi Everyone,
I’m trying to figure out how to get R to analyze this experiment properly. I have a series of subjects each with two legs. Within each leg there are two bones that I am interested in. There are also two treatments that I am interested in. That results in four different combinations of treatments. Obviously, since the subjects only have two legs, they can’t receive each