Displaying 20 results from an estimated 10000 matches similar to: "does lme repeated measures require sphericity?"
2007 Aug 21
2
Sphericity test in R for repeated measures ANOVA
Hi,
Is there a way to do a sphericity test in R for repeated measures ANOVA
(using aov or lme)? I can't find anything about it in the help.
Thanks
Orou
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2007 May 13
2
Some questions on repeated measures (M)ANOVA & mixed models with lme4
Dear R Masters,
I'm an anesthesiology resident trying to make his way through basic
statistics. Recently I have been confronted with longitudinal data in
a treatment vs. control analysis. My dataframe is in the form of:
subj | group | baseline | time | outcome (long)
or
subj | group | baseline | time1 |...| time6 | (wide)
The measured variable is a continuous one. The null hypothesis in
2007 Jun 24
2
ANOVA non-sphericity test and corrections (eg, Greenhouse-Geisser)
I'm an experimental psychologist and when I run ANOVA analysis in
SPSS, I normally ask for a test of non-sphericity (Box's M-test). I
also ask for output of the corrections for non-sphericity, such as
Greenhouse-Geisser and Huhn-Feldt. These tests and correction factors
are commonly used in the journals for experimental and other
psychology reports. I have been switching from SPSS to R
2009 Mar 03
1
repeated measures anova, sphericity, epsilon, etc
I have 3 questions (below).
Background: I am teaching an introductory statistics course in which we are
covering (among other things) repeated measures anova. This time around
teaching it, we are using R for all of our computations. We are starting by
covering the univariate approach to repeated measures anova.
Doing a basic repeated measures anova (univariate approach) using aov()
seems
2009 Dec 01
0
GLM Repeated measures test of assumptions: e.g. test for sphericity e.g. Bartletts and Levenes homogenous variances
Hello and thanks in advance
I am running a glm in R the code is as follows with residual diagnostic code
below
model4<-glm(Biomass~(Treatment+Time+Site)^2, data=bobB,
family=quasi(link="log", variance="mu"))
par(mfrow=c(2,2))
plot(model2)
to test the effect of grazing exclusion of feral horses for a Phd with
following factors:
Treatment - 3 levels which are grazed
2009 Nov 09
1
Getting Sphericity Tests for Within Subject Repeated Measure Anova (using "car" package) (Adjusted Dataset)
[corrected dataset below]
Hello everyone,
I am trying to do within subjects repeated measures anova followed by the
test of sphericity (sample dataset below).
I am able to get either mixed model or linear model anova and TukeyHSD, but
have no luck with Repeated-Measures Assuming Sphericity or Separate
Sphericity Tests.
I am trying to follow example from "car" package, but it seems
2009 Nov 09
1
Getting Sphericity Tests for Within Subject Repeated Measure Anova (using "car" package)
Hello everyone,
I am trying to do within subjects repeated measures anova followed by the
test of sphericity (sample dataset below).
I am able to get either mixed model or linear model anova and TukeyHSD, but
have no luck with Repeated-Measures Assuming Sphericity or Separate
Sphericity Tests.
I am trying to follow example from "car" package, but it seems that I am not
getting something
2007 Oct 16
1
library(car): Anova and repeated measures without between subjects factors
Hi,
sorry if this is explained somewhere but I didn't find anything.
How can I use "Anova" from the car package to test a modell without
between subject's factors? Suppose I have the following data
mat.1 mat.2 mat.3 di ex
1 85 85 88 1 1
2 90 92 93 1 1
3 97 97 94 1 1
4 80 82 83 1 1
5 91 92 91 1 1
6 83 83
2012 Mar 05
2
new to repeated measures anova in R
Data set up as one observation/subject looks like (with a total of 10 subjects)
Two treatments: shoe type with 3 categories and region with 8 categories ==> 24 "treatment" columns
Subject PHallux PMidToes PLatToe PMTH1 PMidMTH PLatMTH PMidfoot PRearfoot LHallux LMidToes LLatToe LMTH1 LMidMTH LLatMTH LMidfoot LRearfoot DHallux DMidToes DLatToe DMTH1 DMidMTH DLatMTH
2005 Nov 15
1
Repeates Measures MANOVA for Time*Treatment Interactions
Dear R folk,
First off I want to thank those of you who responded with comments for
my R quick and dirty stats tutorial. They've been quite helpful, and
I'm in the process of revising them. When it comes to repeated
measures MANOVA, I'm in a bit of a bind, however. I'm beginning to see
that all of the documentation is written for psychologists, who have a
slightly
2011 Sep 22
1
Wrapper of linearHypothesis (car) for post-hoc of repeated measures ANOVA
For some time I have been looking for a convenient way of performing
post-hoc analysis to Repeated Measures ANOVA, that would be acceptable
if sphericity is violated (i.e. leaving aside post-hoc to lme models).
The best solution I found was John Fox's proposal to similar requests
in R-help:
http://tolstoy.newcastle.edu.au/R/e2/help/07/09/26518.html
2007 May 17
2
repeated measures regression
How does one go about doing a repeated measure regression? The
documentation I have on it (Lorch & Myers 1990) says to use linear /
(subj x linear) to get your F. However, if I put subject into glm or
lm I can't get back a straight error term because it assumes
(rightly) that subject is a nominal predictor of some sort.
In looking at LME it seems like it just does the right thing
2012 Mar 21
2
Type II and III sum of squares (R and SPSS)
To whom it may concern
I made some analysis with R using the command Anova. However, I found
some problmes with the output obtained by selecting type II o type III
sum of squares.
Briefly, I have to do a 2x3 mixed model anova, wherein the first factor
is a between factor and the second factor is a within factor. I use the
command Anova in the list below, because I want to obtain also the sum
2011 Mar 10
1
power for repeated-measures ANOVA lacking sphericity
Is there a function that calculates the power of a
repeated-measure ANOVA design, e.g., 2 groups, 4
within-subject factors, an average 0.40 correlation between
the 4 within factors, etc.
I don't think I can use power.anova.test() because it does
not consider corr=0.40.
I am hoping that someone has already implemented the method
by Muller & Barton (1989, JASA 84: 549-555) on how to
2009 Jan 30
3
Q about how to use Anova.mlm
Hi,
Am newish to stats and R, so I certainly appreciate any help. Basically I
have 50 inidividuals whom I have 6 photos each of their optic nerve head. I
want to check that the orientation of the nerve head is consistent, ie the 6
replicates show minimal or preferably no rotation differences. I'll draw an
arbitrary line between some blood vessels (same reference in each set of
replicates) and
2009 Feb 18
2
[package-car:Anova] extracting residuals from Anova for Type II/III Repeated Measures ?
Hello dear R members.
I have been learning the Anova syntax in order to perform an SS type III
Anova with repeated measures designs (thank you Prof. John Fox!)
And another question came up: where/what are the (between/within) residuals
for my model?
############ Play code:
phase <- factor(rep(c("pretest", "posttest", "followup"), c(5, 5, 5)),
2010 Jan 03
1
Anova in 'car': "SSPE apparently deficient rank"
I have design with two repeated-measures factor, and no grouping
factor. I can analyze the dataset successfully in other software,
including my legacy DOS version BMDP, and R's 'aov' function. I would
like to use 'Anova' in 'car' in order to obtain the sphericity tests
and the H-F corrected p-values. I do not believe the data are truly
deficient in rank. I
2013 Nov 16
1
repeated-measures multiple regression/ANCOVA/MANCOVA
Dear List,
I am trying to analyze a dataset where I have 1 continuous
between-item variable (C), and 2 factorial within-item variables (3-
and 2-level: F3, F2). I'm interested in whether slope of C is
different from 0 at different combinations of F3 and F2, and whether
it varies between these combinations.
And unfortunately I need a decent anova-like table with p-values. The
reason is that
2007 Apr 09
1
Repeated Measures design using lme
Hi,
I have what I believe is a repeated-measures dataset that I'm trying to analyze using lme(). This is *not* homework, but an exercise in my trying to self-teach myself repeated-measure ANOVA for other *real* datasets that I have and that are extremely similar to the following design.
I'm fairly sure the dataset described below would work with lme() -- but it'd be great if anybody
2003 Dec 13
0
sphericity calculation (more formulas?)
I believe that the following function is a good function for eyeballing
sphericity. But, I can't find functions for tests anywhere (g-g or
h-f). Anyone who wants to can feel free to use it.
It is bad that R does not provide any tests for sphericity AND cannot
do a MANOVA on repeated measures (although lme is an alternative add on
package). One of these solutions must be provided in the