[R] Sphericity for a repeated measure ANOVA with whithin and between subjects design, using R
peter dalgaard
pdalgd at gmail.com
Tue Jul 7 10:12:54 CEST 2015
Another method goes via anova.mlm(), which is pretty straight forward once you figure out how to set up the necessary within-subject projections (contrasts). See
@Article{Rnews:Dalgaard:2007,
author = {Peter Dalgaard},
title = {New Functions for Multivariate Analysis},
journal = {R News},
year = 2007,
volume = 7,
number = 2,
pages = {2--7},
}
and ?anova.mlm.
-pd
> On 06 Jul 2015, at 18:17 , John Fox <jfox at mcmaster.ca> wrote:
>
> Dear Angelo,
>
> One way to do this is with the Anova() function in the car package; see the
> following article in the R Journal:
>
> @Article{RJournal:2013-1:fox-friendly-weisberg,
> author = {John Fox and Michael Friendly and Sanford Weisberg},
> title = {Hypothesis Tests for Multivariate Linear Models Using the
> {car} Package},
> journal = {The R Journal},
> year = 2013,
> volume = 5,
> number = 1,
> pages = {39--53},
> month = jun,
> url =
> {http://journal.r-project.org/archive/2013-1/RJournal_2013-1_fox-friendly-we
> isberg.pdf}
>
> I hope this helps,
> John
>
>
> -----------------------------------------------
> John Fox, Professor
> McMaster University
> Hamilton, Ontario, Canada
> http://socserv.socsci.mcmaster.ca/jfox/
>
>
>
>> -----Original Message-----
>> From: R-help [mailto:r-help-bounces at r-project.org] On Behalf Of
>> angelo.arcadi at virgilio.it
>> Sent: July-06-15 10:05 AM
>> To: r-help at r-project.org
>> Subject: [R] Sphericity for a repeated measure ANOVA with whithin and
>> between subjects design, using R
>>
>> Dear List Members,
>>
>>
>>
>> I need to perform a four-way ANOVA with repeated measures and to
>> calculate the sphericity for eventual correction of the degree of
>> freedom of the F ratio.
>> I have three within subjects factors (Emotion, having 5 levels,
>> Material, having 4 levels, Shoes, having 2 levels) and a between subject
>> factor (Musician, having 2 levels). Without considering the sphericity
>> I
>> use the following formula
>>
>> aov_SPL = aov(SPL ~ Emotion*Material*Shoes*Musician +
>> Error(Subject/(Emotion*Material*Shoes)), data=scrd)
>>
>>
>>
>> Unfortunately after having read lot of material online I did not
>> arrive to a solution about how to calculate for my case the epsilon of
>> the Greenhouse-Geisser method for degree of freedom adjustment.
>>
>>
>> I load my data in R with this formula:
>>
>> scrd<- read.csv(file='/path to data/data.csv',sep=',',header=T)
>>
>>
>>
>> and this is the structure of the imported table:
>>
>>> head(scrd)
>> Subject Material Shoes Emotion H2H H2H_factor SPL_factor
>> SPL_variation SPL Musician Weight Height
>> 1 Subject1 Gravel dress_shoes AGGRESSIVE 468 0.736 11.591
>> 21.283 97.383 no 90 183
>> 2 Subject1 Gravel dress_shoes HAPPY 719 1.129 3.188
>> 10.071 86.171 no 90 183
>> 3 Subject1 Gravel dress_shoes TENDER 1129 1.774 5.114
>> 14.176 90.276 no 90 183
>> 4 Subject1 Gravel dress_shoes SAD 1010 1.587 13.102
>> 22.347 98.447 no 90 183
>> 5 Subject1 Gravel dress_shoes NEUTRAL 736 1.156 3.161
>> 9.995 86.095 no 90 183
>> 6 Subject10 Gravel dress_shoes AGGRESSIVE 635 0.998 15.849
>> 24.000 100.100 yes 70 178
>>>
>>
>>
>>
>> I noticed that in the car package there is the Anova() function that
>> comes with the Maulchy's sphericity test, but it does not take as an
>> input a model generated with aov(). I need to use lm() instead, but
>> since
>> I am not really proficient in R I do not know how to use the lm()
>> starting from the loaded data and how to use Anova(). In addition, being
>> a mixed design involving within and between subjects factors I wonder
>> if Anova() is the most appropriate function to use for my case.
>>
>>
>> Is there anyone who could provide me with the R code to calculate the
>> Maulchy's test and the epsilon of Greenhouse-Geisser for my case?
>>
>>
>> Thank you in advance
>> Best
>>
>> Angelo
>>
>>
>>
>> [[alternative HTML version deleted]]
>>
>> ______________________________________________
>> R-help at r-project.org mailing list -- To UNSUBSCRIBE and more, see
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>> guide.html
>> and provide commented, minimal, self-contained, reproducible code.
>
>
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> ______________________________________________
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> and provide commented, minimal, self-contained, reproducible code.
--
Peter Dalgaard, Professor,
Center for Statistics, Copenhagen Business School
Solbjerg Plads 3, 2000 Frederiksberg, Denmark
Phone: (+45)38153501
Email: pd.mes at cbs.dk Priv: PDalgd at gmail.com
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