Displaying 20 results from an estimated 900 matches similar to: "a question about glht function"
2009 Nov 03
2
about the cox result
Hi all:
I finished cox analysis like this:
fit_cox<-coxph(Surv(dat$Time, dat$death) ~ dat$CD4 + strata(dat$gender),data=dat);
> fit_cox
Call:
coxph(formula = Surv(data_ori$Time, data_ori$death) ~ data_ori$drug +
strata(data_ori$gender), data = data_ori)
coef exp(coef) se(coef) z p
data_ori$drugddI 0.216 1.24 0.146 1.47 0.14
Likelihood ratio test=2.17 on
2010 Dec 02
5
Tukey Test, lme, error: less than two groups
Dear R-group,
I am trying desperately to get this Tukey test working. Its my first time
here so I hope my question is not too stupid, but I couldn't find anything
helpful in the help or in the forum.
I am analysing a dataset of treated grasses. I want to find out, if the
grasses from different Provenances react differently.
In the aov test I found a significance for the combination Treatment
2013 Oct 01
3
[LLVMdev] RFH: passing options from clang down to opt
I'm trying to add a new option to clang to enable my auto profile
pass. I've added this to Options.td and Driver/Tools.cpp, but I'm not
getting the option -auto-profile in cc1's invocation. I've checked
that the code to push -auto-profile is executed, but if use -v, I
don't see -auto-profile in the cc1 invocation.
Can anyone point me to some document that explains how to
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
2011 Mar 04
2
glht: Problem with symbolic contrast for factors with number-levels
Using a factor with 'number' levels the straightforward
symbolic formulation of a contrast in 'glht' of
the 'multcomp' package fails.
How can this problem be resolved without having to redefine the factor levels?
Example:
#A is a factor with 'number' levels
#B similar factor with 'letter' levels
dat<-data.frame(y=1:4,A=factor(c(1,1,2,2)),
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 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:
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 Aug 06
1
multcomp::glht() doesn't work for an incomplete factorial using aov()?
Hi R users,
I sent a message yesterday about NA in model estimates (
http://r.789695.n4.nabble.com/How-set-lm-to-don-t-return-NA-in-summary-td3722587.html).
If I use aov() instead of lm() I get no NA in model estimates and I use
gmodels::estimable() without problems. Ok!
Now I'm performing a lot of contrasts and I need correcting for
multiplicity. So, I can use multcomp::glht() for this.
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
2008 Apr 15
2
glht with a glm using a Gamma distribution
Quick question about the usage of glht. I'm working with a data set
from an experiment where the response is bounded at 0 whose variance
increases with the mean, and is continuous. A Gamma error
distribution with a log link seemed like the logical choice, and so
I've modeled it as such.
However, when I use glht to look for differences between groups, I get
significant
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
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
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
2008 Jan 11
1
glht() and contrast() comparison
Hi, I have been trying glht() from multcomp package
and contrast() from contrast package to test a
contrast that I am interested in.
With the following simulated dataset (fixed effect
"type" with 3 levels (b, m, t), and random effect
"batch" of 4 levels, a randomized block design with
interaction), sometimes both glht() and contrast()
worked and gave nearly the same p values;
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
2007 May 21
2
more simplified output from glht object
Hi,
I use glht to make multcomp, using Tukey, from a glm model.
It is possible to get a more simplified output of result? Somethink like
ordering by letters.
Thanks
Ronaldo
--
Human kind cannot bear very much reality.
-- T. S. Eliot, "Four Quartets: Burnt Norton"
--
> Prof. Ronaldo Reis J?nior
| .''`. UNIMONTES/Depto. Biologia Geral/Lab. de Ecologia
| : :' :
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 Feb 06
2
glht (multicomparisons) with a binomial response variable
Hi,
I,ve a run a model like this
mcrm<-glm(catroj~month,binomial)
being catroj a binary response variable with two levels (infected and
non infected)
> anova(mcrm3,test="Chisq")
Df Deviance Resid. Df Resid. Dev P(>|Chi|)
NULL 520 149.81
mes 3 16.86 517 132.94 0.0007551 ***
When I?m trying to do a post
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