Displaying 20 results from an estimated 3000 matches similar to: "Problem with lme using glht for multiple comparisons"
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
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
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'!
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))?
>
2012 Jun 22
0
Error with glht function: Error in mcp2matrix(model, linfct = linfct) : Variable(s) 'Type' have been specified in 'linfct' but cannot be found in 'model'!
Dear list members,
I get the following error when using the glht function to perform a post hoc analysis for an ANOVA with repeated measures:
require(nlme)
lme_H2H_musicians = lme(H2H ~ Emotion*Material, data=musicians, random = ~1|Subject)
require(multcomp)
summary(glht(lme_H2H_musicians, linfct=mcp(Type = "Tukey")), test = adjusted(type = "bonferroni"))
Error 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 ***
2012 Nov 07
1
A warning message in glht
Dear all,
I was wondering if you could give me any suggestions/help on the following
issue. So I carried out the analysis of my data using generalized linear
model (glm). After that, to check for multiple comparisons, I applied the
glht function from the multcomp package in R. The output, however, gave me a
warning (please see below). So my question is whether this warning is smth
that I should
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:
2010 Mar 15
1
Multiple comparisons for a two-factor ANCOVA
I'm trying to do an ANCOVA with two factors (clipping treatment with two
levels, and plot with 4 levels) and a covariate (stem diameter). The
response variable is fruit number. The minimal adequate model looks like
this:
model3<-lm(fruit~clip + plot + st.dia + clip:plot)
I'd like to get some multiple comparisons like the ones from TukeyHSD, but
TukeyHSD doesn't work with the
2007 Nov 07
1
bug in multcomp?
I am running a linear model with achiev as the outcome and major as my
iv (5 levels). The lm statement runs fine, but for the glht command I
get the following error. I noted that someone else asked the same
question a while back but received no reply. I am hoping someone might
know what is happening.
anovaf2<-lm(achiev ~ major, data=data_mcp)
> pairwise<- glht(anovaf2,linfct =
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
2011 Feb 08
0
glht{multcomp} : use with lme {nlme}
Hi dears,
I do
> CHOL<-lme(chol~rt*cd4+sex+age+rf+nadir+pharmac+factor(hcv)+factor(hbs)+
haartd+hivdur+factor(arv),
random= ~rt|id, na.action=na.omit)
...runs sweet,..then
....try a multicomparisons approach for the categorical rf
> summary(glht(CHOL, linfct=mcp(rf="Tukey")))
*
Error in model.frame.default(object, data, xlev = xlev) :
l'oggetto non รจ una matrice
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 Nov 05
0
Diference in results from doBy::popMeans, multcomp::glht and contrast::contrast for a lme model
Hello R users,
I'm analyzing an experiment in a balanced incomplet block design (BIB). The
effect of blocks are assumed to be random, so I'm using nlme::lme for this.
I'm analysing another more complex experiments and I notice some diferences
from doBy::popMeans() compared multcomp::glht() and contrast::contrast().
In my example, glht() and contrast() were equal I suspect popMeans()
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
2011 Jul 16
1
Creating composite factor and changing format from character to factor
Dear Help-list, I have a dataframe containing 6 variables, 4 of which are factors, 2 numeric. I want to create another factor variable (SitePos) by combining 2 existing factors (Site and Position). I have tried a number of approaches based on trolling the R FAQs, various R webpages, etc., none of which work. One approach e.g. Data1$SitePos <- paste(Data1$Site, Data1$Position) creates the
2008 Oct 31
0
help with contrasts for a binomial 3-way GLM
Hi
I am a new user the R and I am very grateful for all your help but.......
I have a problem and I can't resolve yet. I am trying to get the contrasts for a binomial 3-way GLM (T= 4 temperature, t= 2 time and c= 2 substrate levels, plus treatment control) in total they are 17 treatments.
I have tried with the glht but this function only work for 1-way GLM,
acacia<-cbind(g,N-g)
2008 Jan 10
1
general linear hypothesis glht() to work with lme()
Hi,
I am trying to test some contrasts, using glht() in
multcomp package on fixed effects in a linear mixed
model fitted with lme() in nlme package. The command I
used is:
## a simple randomized block design,
## type is fixed effect
## batch is random effect
## model with interaction
dat.lme<-lme(info.index~type, random=~1|batch/type,
data=dat)
glht(dat.lme, linfct = mcp(type
2012 Mar 28
1
discrepancy between paired t test and glht on lme models
Hi folks,
I am working with repeated measures data and I ran into issues where the
paired t-test results did not match those obtained by employing glht()
contrasts on a lme model. While the lme model itself appears to be fine,
there seems to be some discrepancy with using glht() on the lme model
(unless I am missing something here). I was wondering if someone could
help identify the issue. On
2012 Jun 14
0
glht multiple comparisons for glm with 2 factors
Hi All,
I have used glm to model my data, I have two factors and a covariate as
described in the example code below (mod.1).
I have been able to "force" glht to perform multiple comparisons by creating
a combined variable for the factors, accepting that there will be a loss of
statistical power as it seems to do what I want. I then use the cld
function to generate the letters of