Displaying 20 results from an estimated 1000 matches similar to: "lme (weights) and glht"
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)),
2011 Jul 26
3
a question about glht function
Hi all:
There's a question about glht function.
My data:data_ori,which inclue CD4, GROUP,time.
f_GROUP<-factor(data_ori$GROUP)
f_GROUP is a factor of 3 levels(0,1,2,3)
result <- lme(sqrt(CD4) ~ f_GROUP*time ,random = ~time|ID,data=data_ori)
glht(result, linfct = mcp(f_GROUP="Tukey") )
Error in `[.data.frame`(mf, nhypo[checknm]) : undefined columns selected
I can't
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 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
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.
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 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
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
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
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
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 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 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 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 ***
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
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;
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
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
2011 Jan 07
4
Problems with glht function for lme object
Dear all,
I'm trying to make multiple comparisons for an lme-object. The data is for
an experiment on parental work load in birds, in which adults at different
sites were induced to work at one of three levels ('treat'; H, M, L). The
response is 'feedings', which is a quantitative measure of nest provisioning
per parent per chick per hour. Site is included as a random effect