Displaying 20 results from an estimated 1000 matches similar to: "Questions about the glht function for planned comparison"
2007 Nov 21
1
multiple comparison (glht) problem
I am not sure whether there is a bug. When I tested the example given for "glht"
in the help, I entered the following error:
Running commands:
amod <- aov(minutes ~ blanket, data = recovery)
rht <- glht(amod, linfct = mcp(blanket = "Dunnett"),
alternative = "less")
Errors are:
Error in try(coef.(model)) : could not find function
2013 Feb 26
1
Getting the correct factor level as Dunnett control in glht()
Hello all,
I would like to do a Dunnett test in glht(). However, the factor level I
want to use as the control is not the first.
dunn1<-glht(model3, linfct = mcp(Container = "Dunnett"), alternative =
"less")
The factor container has 8 levels, so it would be nice not to manually
enter in all of the contrasts. I originally discovered glht() when
working with a glm model
2007 Nov 21
1
question about multiple comparison in ANOVA
I am not sure whether there is a bug. When I tested the example given
for "glht" in the help, I entered the following error:
Running commands:
amod <- aov(minutes ~ blanket, data = recovery)
rht <- glht(amod, linfct = mcp(blanket = "Dunnett"),
alternative = "less")
Errors are:
Error in try(coef.(model)) : could not find function
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 Dec 05
1
Using multcomp::glht() with Anova object
Hello everyone,
I've conducted a Type III repeated-measures ANOVA using Anova() from the
car package, based on the suggestions at
http://blog.gribblelab.org/2009/03/09/repeated-measures-anova-using-r/(option
3) and
http://languagescience.umd.edu/wiki/EEG#ERP_ANOVA_in_R. My ANOVA has two
factors: Condition (3 levels) and Region (6 levels) and their interaction.
Below is code to run the Anova
2012 Jan 13
1
GLHT in multcomp: Two similar models, one doesn't work
i ran this model
> model2<-glm(rojos~ageandsex+sector+season+sector:season,quasipoisson)
> glht(model2,linfct=mcp(ageandsex="Tukey"))
General Linear Hypotheses
Multiple Comparisons of Means: Tukey Contrasts
Linear Hypotheses:
Estimate
M - H == 0 0.2898
SUB - H == 0 -0.2261
SUB - M == 0 -0.5159
I tried to do the same changing factor season
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
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
2010 Sep 14
4
Problems with "pdf" device using "plot" "glht" function on "multcomp" library.
Hi R users:
I have de following data frame (called "Sx")
Descripcion Nitratos
Cont85g 72.40
Cont85g 100.50
Cont85g 138.30
Cont80g 178.33
Cont80g 79.01
Cont80g 74.16
Cont75g 23.70
Cont75g 15.80
Cont75g 16.20
Patron80g
2013 Oct 12
1
export glht to LaTeX
Hi,
I want to export the result of glht in R into a LaTeX table, such as that result:
Linear Hypotheses:
Estimate Std. Error z value Pr(>|z|)
Group1 - Group2 == 0 -0.14007 0.01589 -8.813 <0.001 "***"
Group1 - Group3 == 0 -0.09396 0.01575 -5.965 <0.001 ***
---
Signif. codes: 0 ?***? 0.001 ?**? 0.01 ?*? 0.05
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
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)
2007 Feb 09
1
Help in using multcomp.
Hi All,
I am trying use 'multcomp' for multiple comparisons
after my ANOVA analysis. I have used the following
code to do ANOVA:
dat <- matrix(rnorm(45), nrow=5, ncol=9)
f <- gl(3,3,9, label=c("C", "Tl", "T2"))
aof <- function(x) {
m <- data.frame(f, x);
aov(x ~ f, m)
}
amod <- apply(dat,1,aof)
Now, how can I use
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
2013 Oct 27
1
dunnett test questions
Hi,
I've got a data set with a control group and a number of experimental
groups, that have unequal sample sizes, and am measuring the number of
people in each that respond yes or no. I'd like to use a dunnett test in
R, where the syntax is supposed to be like:
library(multcomp)
test.dunnett=glht(anova_results,linfct=mcp(method="Dunnett"))
confint(test.dunnett)
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
2011 Sep 28
0
Trouble with performing post hoc analysis Tukey for lme model using ghlt
Hi,
I am new to R and I am trying to perform a post hoc tukey test using the
multcomp package's ghlt for a lme model. My first attempt at doing so gave
me an output, HOWEVER I have tried to do this again, it keeps coming up with
the error:
(Error in contrMat(table(mf[[nm]]), type = types[pm]) :
less than two groups)
My model is looking at effect of incubation temperature (3 groups) on
2009 Dec 15
1
error when using multcomp and lm
I am trying to use multcomp to do a Tukey posthoc on growth increments among
genetic crosstypes.
#Fixed effect model
m1 <- lm(inc ~ 0 + Age+ Crosstype + Sex, data = Data.age)
summary(m1)
RESULTS of the model:
summary(m1)
Call:
lm(formula = inc ~ 0 + Age + Crosstype + Sex, data = Data.age)
Residuals:
Min 1Q Median 3Q Max
-0.87180 -0.34002 -0.02702 0.27710 2.17820
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
2011 Sep 22
1
How to do Multiple Comparisons for a Mixed Effects Model
Hello everyone I am currently trying to conduct analysis of my graduate thesis data using a mixed effects model and I have reached an impass. When I try to conduct a multiple comparison, I get an error (See below): > fm3<- lme(abovegroundbiomass.m.2~medium*amelioration*fertilizer*treatment, random=~1|block/medium/amelioration/fertilizer) > tukeytest<-glht(fm3,