Displaying 20 results from an estimated 3000 matches similar to: "Tukey test for subgroups in a data frame"
2012 Dec 13
1
Physically extracting P-value from TukeyHSD test output
Hey,
I have this TukeyHSD output from which I would like to extract only the
P-values (p adj, last number).
The problem is that the test output is a character list.
How can I "break" this sentence to separate the Pv?
Tukey multiple comparisons of means
95% family-wise confidence level
Fit: aov(formula = Fe1$Fe ~ Fe1$genotype)
$`Fe1$genotype`
diff lwr upr
2012 Apr 20
4
Problem with Tukey test
I'm new using R im trying to do a tukey test, but when i see the results the
p value results in NA im guessing its because i have missing values but im
not sure how to fix it
AnovaModel.2 <- aov(area ~ trat, data=apilados)
> summary(AnovaModel.2)
Df Sum Sq Mean Sq F value Pr(>F)
trat 4 11847 2961.76 9.9905 1.500e-06 ***
Residuals 76 22531 296.46
2010 Oct 22
2
visualize TukeyHSD results
I am a new R user but a long time SAS user. I searched for a response to this question but no luck, so forgive me if this topic has been covered before. I am running a TukeyHSD post hoc test after running an ANOVA. I get the results of all pairwise comparisons, no problem. However, the output table is a little "busy", and I'd like to make the output easier to read. Specifically, I
2007 Mar 02
4
significant anova but no distinct groups ?
Dear all,
I am studying a dataset using the aov() function.
The independant variable 'cds' is a factor() with 8 levels and here is
the result in studying the dependant variable 'rta' with aov() :
> summary(aov(rta ~ cds))
Df Sum Sq Mean Sq F value Pr(>F)
cds 7 0.34713 0.04959 2.3807 0.02777
Residuals 92 1.91635 0.02083
The dependant variable
2010 Apr 29
1
R Anova Analysis
Dear all,
I have a quite basic questions about anova analysis in R, sorry for
this, but I have no clue how to explain this result.
I have two datasets which are named: nmda123, nmda456. Each dataset has
three samples which were measured three times. And I would like to
compare means of them with Posthoc test using R, following please see
the output:
(CREB, mCREB and No virus are the name of
2004 Dec 15
1
TukeyHSD & Covariates
Dear R gurus,
I have the following model:
appcov.aov <- aov(yield ~ prevyield + trt + block)
where prevyield is a continuous numeric covariate and trt and block are
factors (yes, I did factor()!)
Now, when I do a TukeyHSD, my diff's are all screwed up!
For instance:
treatment mean for treatmen "E" is 277.25 and for treatment "O" is
279.5, so I figure the diff O-E
2003 Aug 13
1
anova and tukeyHSD
I would like to do a one way anova and then a tukeyHSD. I have three vectors
A,B and C. In a previous help message, I was told to do the following for
the anova:
y = c(A,B,C)
group = factor(rep(a:3,c(7,9,13))) #provided there a 7 elements in A,9 in B
and 13 in C
and then
anova(lm(y~group))
Looking at the tukeyHSD method it looks like it wants the aov method which I
don't understand.
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
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
2004 Aug 19
1
Question on TukeyHSD
Hi,
I am running a ANOVA on a factorial design, and using TukeyHSD
for post hoc comparisons. I have 2 factors with three levels each:
Factor B
Factor A 1 2 3
1
2
3
When I look at the Tukey output (on the interaction of the factors) the
comparisons come out numbered 1-36.
e.g.
$"A:B"
diff lwr upr
[1,] 49.1666667 -160.041022 258.3744
[2,]
2005 May 15
3
adjusted p-values with TukeyHSD?
hi list,
i have to ask you again, having tried and searched for several days...
i want to do a TukeyHSD after an Anova, and want to get the adjusted
p-values after the Tukey Correction.
i found the p.adjust function, but it can only correct for "holm",
"hochberg", bonferroni", but not "Tukey".
Is it not possbile to get adjusted p-values after
2011 Feb 26
1
Pulling p values
Hi folks,
I'm doing ANOVA with multiple comparisons. I've used both the TukeyHSD function and the multcomp procedure. In both cases, I get some tantalizing results such as this...
e = aov(lm(d.all[,(n+4)] ~ d.all[,4])
TukeyHSD(e)
Tukey multiple comparisons of means
95% family-wise confidence level
Fit: aov(formula = lm(d.all[, (n + 4)] ~ d.all[, 4], contrast = C))
$`d.all[,
2003 Jan 30
1
TukeyHSD and BIBD
Hi,
the function TukeyHSD gives incorrect results for balanced incomplete block
designs, as the example below shows, but I can only half fix it. There are
two problems,
1. It uses model.tables to estimate treatment means,
2. It uses the wrong standard error
The first problem can be fixed using dummy.coef, if the lines
> TukeyHSD.aov
function (x, which = seq(along = tabs), ordered = FALSE,
2008 Sep 17
1
ANOVA contrast matrix vs. TukeyHSD?
Dear Help List,
Thanks in advance for reading...I hope my questions are not too ignorant.
I have an experiment looking at evolution of wing size [centroid] in
fruitflies and the effect of 6 different experimental treatments
[treatment]. I have five replicate populations [replic] in each
treatment and have reared the flies in two different temperatures [cond]
to assay the wing size, making
2012 May 14
2
How to interpret an ANOVA result?
Hello all,
here's a real-world example: I'm measuring a quantity (d) at five
sites (site1 thru site5) on a silicon wafer. There is a clear
site-dependence of the measured value. To find out if this is a
measurement artifact I measured the wafer four times: twice in the
normal position (posN), and twice rotated by 180 degrees (posR). My
data looks like this (full, self-contained code at
2010 Jun 12
1
Displaying "homogeneous groups" in aov post-hoc results ?
Hello dear R-help mailing list,
A friend of mine teaches a regression and experimental design course and
asked me the following question.
She is trying to find a way to display the "homogeneous groups" (after
performing tukey test on an aov object).
here's an example for what she means by "homogeneous groups":
She did one way anova and got these results for tukey test:
2013 Mar 13
1
multi-comparison of means
Hi all:
I have a question about multi-comparison.
The data is in the attachment.
My purpose:
Compare the predicted means of the 3 methods(a,b,c) pairwisely.
I have 3 ideas:
#idea1
result_aov<-aov(y~ method + x1 + x2)
TukeyHSD(result_aov)
diff lwr upr p adj
b-a 0.845 0.5861098 1.1038902 0.0000001
c-a 0.790 0.5311098 1.0488902 0.0000002
c-b -0.055 -0.3138902
2013 Jan 23
1
italic font for legend text when using expression function for symbols
Hello,
I'm trying to add a symbol (Delta) to plot legend with text using
"expression(paste())" but this disables the text.font that allows to use
bold or italic text.
as follows:
x=c(1:10)
y=c(1:10)
plot(x,y)
legend(1,10,legend=c("A","B","C",expression(paste(Delta, D))),
pch=c(24,18,17,16),cex=2,text.font=3,bty="n")
Any suggestion to
2008 Dec 02
1
QQ plots and boxcox
Dear R People:
In the DASL library, there is a story about hot dogs.
Here are the data:
Beef 186 495
Beef 181 477
Beef 176 425
Beef 149 322
Beef 184 482
Beef 190 587
Beef 158 370
Beef 139 322
Beef 175 479
Beef 148 375
Beef 152 330
Beef 111 300
Beef 141 386
Beef 153 401
Beef 190 645
Beef 157 440
Beef 131 317
Beef 149 319
Beef 135 298
Beef 132 253
Meat 173 458
Meat 191 506
Meat 182 473
Meat 190