Displaying 20 results from an estimated 300 matches similar to: "environments again"
2004 Aug 12
0
Re: R-help Digest, Vol 18, Issue 12
The message for aov1 was "Estimated effects <may> be unbalanced". The
effects are not unbalanced. The design is 'orthogonal'.
The problem is that there are not enough degrees of freedom to estimate
all those error terms. If you change the model to:
aov1 <-
aov(RT~fact1*fact2*fact3+Error(sub/(fact1+fact2+fact3)),data=myData)
or to
aov2 <-
2013 Apr 05
0
(no subject)
Hello,
I am running error rate analysis. It is my results below. When I compare
aov1 and aov2, X square = 4.05, p = 0.044, which indicates that adding the
factor "Congruity" improved the fitting of model. However, the following Z
value is less than 1 and p value for Z is 1, which means that "Congruity"
is not significant at all. Therefore, these two parts are not consistent,
2001 Dec 12
1
again evaluations
Hello, I wrote the following function to compute multiple comparisons in
a one way anova and randomized blocks anova.
aov1 <- function(y,g,s=NULL,comp="mca",meth="Sidak") {
#
fun <- function(x)
c(mean(x,na.rm=T),sd(x,na.rm=T),length(x[!is.na(x)]))
#
li <- length(unique(g))
cat(" Analysis of Variance with Multiple comparisons\n\n")
cat("
2011 May 21
0
Problem with ANOVA repeated measures: "Error() model is singular"
Hello everybody,
I need an help because I don´t know if the command for the ANOVA analysis I am
performing in R is correct. Indeed using the function aov I get the following error:"In aov (......) Error() model is singular"
The structure of my table is the following: subject, stimulus, condition, sex, response
Example:
subject stimulus condition sex response
2005 Oct 28
2
Random effect models
Dear R-users,
Sorry for reposting. I put it in another way :
I want to test random effects in this random effect model :
Rendement ~ Pollinisateur (random) + Lignee (random) + Pollinisateur:Lignee (random)
Of course :
summary(aov(Rendement ~ Pollinisateur * Lignee, data = mca2))
gives wrong tests for random effects.
But :
summary(aov1 <- aov(Rendement ~ Error(Pollinisateur * Lignee), data =
2005 Oct 27
2
F tests for random effect models
Dear R-users,
My question is how to get right F tests for random effects in random effect models (I hope this
question has not been answered too many times yet - I didn't find an answer in rhelp archives).
My data are in mca2 (enc.) :
names(mca2)
[1] "Lignee" "Pollinisateur" "Rendement"
dim(mca2)
[1] 100 3
replications(Rendement ~ Lignee *
2011 Jan 07
2
anova vs aov commands for anova with repeated measures
Dear all,
I need to understand a thing in the beheaviour of the two functions aov and
anova in the following case
involving an analysis of ANOVA with repeated measures:
If I use the folowing command I don´t get any problem:
>aov1 = aov(response ~ stimulus*condition + Error(subject/(stimulus*condition)),
>data=scrd)
> summary(aov1)
Instead if I try to fit the same model for the
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
2001 Dec 23
1
aov for mixed model (fixed and random)?
I'm starting to understand fixed and random effects, but I'm
puzzled a bit. Here is an example from Hays's textbook (which is
great at explaining fixed vs. random effects, at least to dummies
like me), from the section on mixed models. You need
library(nlme) in order to run it.
------
task <- gl(3,2,36) # Three tasks, a fixed effect.
subj <- gl(6,6,36) # Six subjects, a random
2009 Oct 27
0
anova interaction contrasts: crossing helmert and linear contrasts
I am new to statistics, R, and this list, so apologies in advance for
the errors etiquette I am certain to make (in spite of reading the
posting guide, help on
various commands, etc.). ?Any help is greatly appreciated.
Here is my data:
fatigue = c(3,2,2,3,2,3,4,3,2,4,5,3,3,2,4,5,4,5,5,6,4,6,9,8,4,3,5,5,6,6,6,7,9,10,12,9)
n <- 3
train <- gl(3, 4*n, labels=c("6wks",
2012 Apr 15
0
correct implementation of a mixed-model ANOVA in R
Dear R-experts!
I having trouble with the correct implementation of a mixed-model ANOVA in
R.
I my dataset subjects were tested in a cognitive performance test
(numerical outcome variable 'score'). This cognitive performance test is
devided into five blocks (categorical factor 'block'). All subjects were
tested two times (in random order once following placebo treatment and once
2011 Jan 08
1
Anova with repeated measures for unbalanced design
Dear all,
I need an help because I am really not able to find over internet a good example
in R to analyze an unbalanced table with Anova with repeated measures.
For unbalanced table I mean that the questions are not answered all by the same
number of subjects.
For a balanced case I would use the command
aov1 = aov(response ~ stimulus*condition + Error(subject/(stimulus*condition)),
data=scrd)
2009 Apr 07
1
Pulling data into a model
I'm creating an ANOVA model. Is there a way to pull in consecutive columns of variables for the test?
Example: aov1<-aov(y~x1+x2+REG[,2:num], data=REG)
I'm not looking for interaction effects, I just want to create a model for the first few columns of variables (exact number and names will vary) and a few other predetermined variables (in the example I named them x1 and x2).
Thanks
2013 Jan 27
1
decimal places in R2HTML
Dear R People:
I have an AOV model that I get confidence intervals from via
> confint(chick1.aov1)
2.5 % 97.5 %
trtA 1.472085 1.607915
trtB 1.512085 1.647915
trtC 1.328751 1.464582
>
I am using R2HTML to produce HTML output. However, the HTML code
itself just has rounded values, i.e., 1.5 and 1.6.
Has anyone run across this, please?
Any suggestions would be much appreciated.
2004 Aug 11
1
Fwd: Enduring LME confusion… or Psychologists and Mixed-Effects
In my undertstanding of the problem, the model
lme1 <- lme(resp~fact1*fact2, random=~1|subj)
should be ok, providing that variances are homogenous both between &
within subjects. The function will sort out which factors &
interactions are to be compared within subjects, & which between
subjects. The problem with df's arises (for lme() in nlme, but not in
lme4), when
2004 Aug 10
4
Enduring LME confusion… or Psychologists and Mixed-Effects
Dear ExpeRts,
Suppose I have a typical psychological experiment that is a
within-subjects design with multiple crossed variables and a continuous
response variable. Subjects are considered a random effect. So I could model
> aov1 <- aov(resp~fact1*fact2+Error(subj/(fact1*fact2))
However, this only holds for orthogonal designs with equal numbers of
observation and no missing values.
2004 Jan 30
0
Two apparent bugs in aov(y~ *** -1 + Error(***)), with suggested (PR#6510)
I think there are two bugs in aov() that shows up when the right hand
side of `formula' contains both `-1' and an Error() term, e.g.,
aov(y ~ a + b - 1 + Error(c), ...). Without `-1' or `Error()' there
is no problem. I've included and example, and the source of aov()
with suggested fixes below.
The first bug (labeled BUG 1 below) creates an extra, empty stratum
inside
2004 Feb 02
0
Two apparent bugs in aov(y~ *** -1 + Error(***)), with (PR#6520)
I believe you are right, but can you please explain why anyone would want
to fit this model? It differs only in the coding from
aov(y ~ a + b + Error(c), data=test.df)
and merely lumps together the top two strata.
There is a much simpler fix: in the line
if(intercept) nmstrata <- c("(Intercept)", nmstrata)
remove the condition (and drop the empty stratum later if you
2008 Aug 17
1
before-after control-impact analysis with R
Hello everybody,
In am trying to analyse a BACI experiment and I really want to do it
with R (which I find really exciting). So, before moving on I though it
would be a good idea to repeat some known experiments which are quite
similar to my own. I tried to reproduce 2 published examples but without
much success. The first one in particular is a published dataset
analysed with SAS by
2003 Jun 17
1
lme() vs aov(y ~ A*B + Error(aa %in% A + bb %in% B)) [repost]
I've posted the following to R-help on May 15.
It has reproducible R code for real data -- and a real
(academic, i.e unpaid) consultion background.
I'd be glad for some insight here, mainly not for myself.
In the mean time, we've learned that it is to be expected for
anova(*, "marginal") to be contrast dependent, but still are
glad for advice if you have experience.
Thank