Displaying 20 results from an estimated 10000 matches similar to: "simple main effect."
2006 Dec 28
1
split-plot multiple comparisons
Dear R user,
I am new with split-plot designs and I have problems with multiple comparisons.
This data correspond to an split-plot experiment with two replications
(bloque).(Hoshmand, 2006 pp 138). Briefly, the whole-plot factor is
Nitrogen concentration ("nitrogeno") and the subplot factor is the variety
of corn ("hibrido"). The aim is to determine if major differences
2007 Mar 25
1
anova-interaction
HI,
I am trying to perform ANOVA with 2 factors:
material (3), temperature(3). The interaction is significant. I tried
something like, ( summary(avt, split=list("temp:mat"=list("15"=1,
"70"=2, "125"=3))) is not correct).
Thanks,
av <- aov(time ~ mat*temp, data=dados)
avt <- aov(time ~ temp/mat)
summary(avt,
2010 Nov 23
2
factorial ANOVA for block/split-plot design
Dear R Help -
I am analyzing data from an ecological experiment and am having problems
with the ANOVA functions I've tried thus far. The experiment consists of a
blocked/split-plot design, with plant biomass as the response. The following
is an overview of the treatments applied (nitrogen addition, phosphorus
addition, and seeded/not seeded) and at what level (block, main-plot, and
sub-plot):
2007 Jan 09
2
posthoc tests with ANCOVA
dear all,
I want to perform a posthoc test for my ANCOVA:
a1<-aov(seeds~treatment*length)
With
summary(glht(a1, linfct = mcp(treatment = "Tukey")))
R tells me: "covariate interactions found -- please choose appropriate
contrast"
How do I build these contrasts?
Ideally, I would like to have the posthoc test for the ANCOVA including
a block-effect
2010 Oct 06
2
ANOVA boxplots
Dear list,
i have a quick and (hopefully) straightforward question regarding the
plot-function after running aov. if i plot an equation like this:
plot(dataSubjects~factorA, data=mydata)
R gives me the boxplots for this particular factor A. my model, however
contains several factors. is there a straightforward way to plot barplots
for a specific factor with the constraint that those values
2010 Feb 09
1
Interpretation of high order interaction terms.
I have difficulties in interpreting high order interaction terms in
high-way ANOVA.
According to Introductory Statistics with R by Peter Dalgaard (Section 12.5),
"The exact definition of the interaction terms and the interpretation of their
associated regression coefficients can be elusive. Some peculiar things
happen if an interaction term is present but one or more of the main
effects are
2011 Jan 09
2
Post hoc analysis for ANOVA with repeated measures
Dear all,
how can I perform a post hoc analysis for ANOVA with repeated measures (in
presence of a balanced design)?
I am not able to find a good example over internet in R...is there among you
someone so kind to give
me an hint with a R example please?
For example, the aov result of my analysis says that there is a statistical
difference between stimuli (there are 7 different stimuli).
...I
2010 Jun 09
3
comparing two regression models with different dependent variable
Hi,
I would like to compare to regression models - each model has a different
dependent variable.
The first model uses a number that represents the learning curve for reward.
The second model uses a number that represents the learning curve from
punishment stimuli.
The first model is significant and the second isn't.
I want to compare those two models and show that they are significantly
2010 Mar 13
1
Help needed: Split-split plot analysis
Hello,
I am very new to R but would like to use the software to analyse the
attached data. The experiment followed a split-split plot design
There were two blocks and the whole plot is CO2 with two levels. The
sub-plot is soil temperature with three levels and the sub-sub plot is soil
moisture content with three levels (low, intermediate and high-similar for
soil temperature). I had 7 plants per
2010 Feb 21
2
plot is not keeping the order of variable
Hi,
I created a simple data frame with one factor and one numerical variable.
The factor was actually a vector of names of techniques to trimm reaction
time data.
I want to create a plot that shows the value of F test for every trimming
method.
So the data frame has its trim factor (who has those labels
2008 May 28
2
Tukey HSD (or other post hoc tests) following repeated measures ANOVA
Hi everyone,
I am fairly new to R, and I am aware that others have had this
problem before, but I have failed to solve the problem from previous
replies I found in the archives.
As this is such a standard procedure in psychological science, there
must be an elegant solution to this...I think.
I would much appreciate a solution that even I could understand... ;-)
Now, I want to calculate a
2007 Jun 28
2
TukeyHSD
Hello everyone,
So I ran an anova with aov and then I want to run post-hoc comparisons but
keep receiving this message :
> no applicable method for "TukeyHSD"
Here is my code:
> d<-read.table("d.txt")
> d
> Obs subj Hand Gaze RT
> 1 1 s1 1 1 401.4
> 2 2 s2 1 1 363.3......
> summary(ano <-
2009 Nov 20
1
Help with multiple comparisons on a 2-way repeated measures ANOVA
Hi everyone,
I'm trying to do a 2-way repeated measures ANOVA with data that looks like
this:
subject block rep day light response
1 1 1 one L1 5.5
2 1 2 one L1 4.5
3 1 1 one L2 4
4 1 2 one L2 5.1
5 2 1 one L1 5.3
6 2 2 one L1
2008 Aug 24
1
Plotting 3 way Anova
Hi
I'd really like to get a bar plot showing the means of my anova data. I have looked everywhere and can only seem to find instructions for 2 way anova's.
I basically want to look at the mean condition of my subjects spilt by age, sex and year (as a factor rather than a continuous variable, hence Anova and not Ancova). and want to show it firstly as a bar graph with standard error. I
2010 Feb 17
2
Split Plot and Tukey
Hi,
I did the analysis of variance of a split-plot and the
effect of treatment was significant.
I would like compare treatment means using Tukey.
I can't extract the mean square to apply HSD.test to use in
agricolae package.
anava = aov(ganhos ~ Blocos + Trat*Supl +
Error(Blocos/Trat))
names(anava)
summary(anava)
require(agricolae)
HSD.test(ganhos, Trat, df, MSerror, alpha = 0.05)
2009 Nov 27
2
using reshape to do ANOVA mixed models
Hi,
I just started with R and I found that there are many options to rearrange
the data to do mixed models.
I want to use the reshape function. I have 2 between subject variables and
one within.
I was able to change the data structure but still - the result of the aov
functions are calculating everything as a within subject.
the table looks like this:
SerialNo breed treatment distance_1
2007 Jun 12
1
Post-hoc tests for interactions of between- and within-subject factors
Is there a standardized way in R to perform post-hoc comparisons for main
adn interaction effects of between- and within-subject factors?
For instance, I have a data set of performance of adults of different age
groups (20-30, 60-70,70-80) performing a WM task (n-back, with n=1,2,3,4) in
two different conditions (while sitting or walking). The corresponding ANOVA
produces the following output
2007 Apr 09
1
How to solve differential and integral equation using R?
Hello,
I want to know if there are some functions or packages to solve differential
and integral equation using R.
Thanks.
Shao chunxuan.
[[alternative HTML version deleted]]
2009 Oct 07
2
Plotting 1 covariate, 3 factors
I'm interested in plotting a y with an x factor as the combination of 2
factors and colour with respect to a third, which the code below does with
interaction.plot(). However, this is because I redefine the x to be 1
factor. Is there a way of getting it to plot without redefining it, and
ideally to not join up the lines BETWEEN levels a and b, but just join those
between after and before for
2010 Mar 06
2
Plot interaction in multilevel model
I am trying to plot an interaction in a multilevel model. Here is some
sample data. In the following example, it is longitudinal (i.e., repeated
measures), so the outcome, score (at each of the three time points), is
nested within the individual. I am interested in the interaction between
gender and happiness predicting score.
id <- c(1,1,1,2,2,2,3,3,3)
age <-