Displaying 20 results from an estimated 3000 matches similar to: "TukeyHSD changes if I create interaction term"
2004 May 14
0
Work around for TukeyHSD names
R Version 2.0.0 Under development (unstable) (2004-05-07)
I have been wanting to use TukeyHSD for two and three way aov's, as
they are especially simple for students to use correctly. I realize
model simplification is usually a preferred methodology, but my
disciplinary enertia and simplicity of TukeyHSD is also compelling.
However, the lack of names on the comparisons for the higher order
2012 May 16
1
TukeyHSD plot error
Hi, I am seeking help with an error when running the example from R
Documentation for TukeyHSD. The error occurs with any example I run, from
any text book or website. thank you...
> plot(TukeyHSD(fm1, "tension")).
Error in plot(confint(as.glht(x)), ylim = c(0.5, n.contrasts + 0.5), ...) :
error in evaluating the argument 'x' in selecting a method for function
2005 Jul 15
1
Adjusted p-values with TukeyHSD (patch)
Dear R-developeRs,
Attached follows a patch against svn 34959 that adds the
printing of p-values to the TukeyHSD.aov function in stats package. I
also updated the corresponding documentation file and added a 'see also'
reference to the simint function of the multcomp package.
As it was already brought up in a previous thread [1] in R-help,
one can obtain the adjusted
2006 Aug 01
1
plot() with TukeyHSD
Hello,
When plotting the results of a TukeyHSD multiple comparisons
procedure with an ANOVA (lm) object, an extra line appears
in the confidence intervals that contain 0. For example (this
is straight from the TukeyHSD helpfile):
> summary(fm1 <- aov(breaks ~ wool + tension, data = warpbreaks))
> TukeyHSD(fm1, "tension", ordered = TRUE)
> plot(TukeyHSD(fm1,
2012 Oct 23
1
How Rcmdr or na.exclude blocks TukeyHSD
Dear R-Helpers,
I was calling the TukeyHSD function and not getting confidence intervals or p-values. It turns out this was caused by missing data and the fact that I had previously turned on R Commander (Rcmdr). John Fox knew that Rcmdr sets na.action to na.exclude, which causes the problem. If you have this problem, you can either exit Rcmdr before calling TukeyHSD or you can set na.action to
2008 Apr 28
0
restricting pairwise comparisons of interaction effects
I'm interested in restricting the pairwise comparisons of interaction
effects in a multi-way factorial ANOVA, because I find comparisons of
interactions between all different variables different to interpret.
For example (supposing a p<0.10 cutoff just to be able to use this
example):
> summary(fm1 <- aov(breaks ~ wool*tension, data = warpbreaks))
Df Sum Sq Mean Sq F
2008 May 01
0
customization of pairwise comparison plots
I am wondering how to customize a pairwise comparisons plot of a factorial
ANOVA, without doing a lot of manual manipulation of a TukeyHSD object. The
customizations I'd like are:
1. The aov used log-transformed response data, but I'd like to plot the
intervals on their original, untransformed scales
2. Plot all the main and interaction effects together, rather than in a
separate
2006 Jan 15
1
Multiple comparison and two-way ANOVA design
Dear useRs,
I'm working on multiple comparison design on two factor (2 3 levels)
ANOVA. Each of the tests I have tried (Tukey, multcomp package) seem to
do only with one factor at a time.
fm1 <- aov(breaks ~ wool * tension, data = warpbreaks)
tHSD <- TukeyHSD(fm1, "tension", ordered = FALSE)
$tension
diff lwr upr p adj
M-L -10.000000 -19.35342
2012 Apr 26
0
Some graphical parameters don't works in plot.table and plot.TukeyHSD.
Hello all,
I would like to relate this behaviour of: plot.table & plot.TukeyHSD.
They don't work with some graphical parameters.
Thanks for your attetion.
Cleber
> ### example:
> plot( table(1:10), cex.axis=0.6)
> plot( table(1:10), las=2)
>
> tukaov <- TukeyHSD( aov(breaks ~ wool + tension, data = warpbreaks) )
>
> plot( tukaov, main='xxx' )
Error
2018 Jan 09
0
SpreadLevelPlot for more than one factor
Dear Sir,
Many thanks for your reply.
I have a query.
I have a whole set of distributions which should be made normal /
homoscedastic. Take for instance the warpbreaks data set.
We have the following boxplots for the warpbreaks dataset:
a. boxplot(breaks ~ wool)
b. boxplot(breaks ~ tension)
c. boxplot(breaks ~ interaction(wool,tension))
d. boxplot(breaks ~ wool @ each level of tension)
e.
2018 Jan 14
1
SpreadLevelPlot for more than one factor
Dear Ashim,
I?ll address your questions briefly but they?re really not appropriate for
this list, which is for questions about using R, not general statistical
questions.
(1) The relevant distribution is within cells of the wool x tension
cross-classification because it?s the deviations from the cell means that
are supposed to be normally distributed with equal variance. In the
warpbreaks data
2018 Jan 07
2
SpreadLevelPlot for more than one factor
Dear All,
I want a transformation which will make the spread of the response at all
combinations
of 2 factors the same.
See for example :
boxplot(breaks ~ tension * wool, warpbreaks)
The closest I can do is :
spreadLevelPlot(breaks ~tension , warpbreaks)
spreadLevelPlot(breaks ~ wool , warpbreaks)
I want to do :
spreadLevelPlot(breaks ~tension * wool, warpbreaks)
But I get :
>
2018 Jan 07
0
SpreadLevelPlot for more than one factor
Dear All,
we need to do :
library(car) for the spreadLevelPlot function
I forgot to say that.
Apologies,
Ashim
On Sun, Jan 7, 2018 at 10:37 AM, Ashim Kapoor <ashimkapoor at gmail.com> wrote:
> Dear All,
>
> I want a transformation which will make the spread of the response at all
> combinations
> of 2 factors the same.
>
> See for example :
>
>
2006 Oct 27
0
glht for aov with Error() term
Dear all,
glht (from the multcomp package) needs a term and a model component
in it's fitted model.
In fitted models from e.g. repeated measurements ANOVAs I do not find
neither model nor term.
Is it possible to build together a model and term component myself,
so that glht will work for repeated measurements ANOVAs? If so, how
would I do that?
Best regards,
Michael Zehetleitner
2012 Jul 27
1
Understanding the intercept value in a multiple linear regression with categorical values
Hi!
I'm failing to understand the value of the intercept value in a
multiple linear regression with categorical values. Taking the
"warpbreaks" data set as an example, when I do:
> lm(breaks ~ wool, data=warpbreaks)
Call:
lm(formula = breaks ~ wool, data = warpbreaks)
Coefficients:
(Intercept) woolB
31.037 -5.778
I'm able to understand that the value of
2018 Jan 07
2
SpreadLevelPlot for more than one factor
Dear Ashim,
Try spreadLevelPlot(breaks ~ interaction(tension, wool), data=warpbreaks) .
I hope this helps,
John
-----------------------------
John Fox, Professor Emeritus
McMaster University
Hamilton, Ontario, Canada
Web: socialsciences.mcmaster.ca/jfox/
> -----Original Message-----
> From: R-help [mailto:r-help-bounces at r-project.org] On Behalf Of Ashim
> Kapoor
> Sent:
2007 Aug 14
4
Problem with "by": does not work with ttest (but with lme)
Hello,
I would like to do a large number of e.g. 1000 paired ttest using the by-function. But instead of using only the data within the 1000 groups, R caclulates 1000 times the ttest for the full data set(The same happens with Wilcoxon test). However, the by-function works fine with the lme function.
Did I just miss something or is it really not working? If not, is there any other possibility to
2012 Nov 29
2
Deleting certain observations (and their imprint?)
I'm manipulating a large dataset and need to eliminate some observations based on specific identifiers. This isn't a problem in and of itself (using which.. or subset..) but an imprint of the deleted observations seem to remain, even though they have 0 observations. This is causing me problems later on. I'll use the dataset warpbreaks to illustrate, I apologize if this isn't in
2013 Feb 25
1
quesion about SS of ANOVA
Hi all:
I have a quesion about ANOVA: Is SS(Sum of Square) of a specific factor constant with the number of factors changing?
dat1 includes one factor g1,and g1's SS is called SS_g1_dat1.
dat2 includes two factors g1,g2,and g1's SS is called SS_g1_dat2.
My quesion is: Is SS_g1_dat1 equals to SS_g1_dat2?
I have both "yes" and "no" reasons for the quesion,but
2010 May 18
2
how to select rows per subset in a data frame that are max. w.r.t. a column
Hi,
I'd like to select one row in a data frame per subset which is maximal for a
particular value. I'm pretty close to the solution in the sense that I can
easily select the maximal values per subset using "aggregate", but I can't
really figure out how to select the rows in the original data frame that are
associated with these maximal values.
library(stats)
# this