Hello all,
I am a 2 month newbie to R and am stumped. I have a data set that I've run
multivariate stats on using the manova function (I included the data set). Now
it comes time for a table of effect sizes with significance. The univariate
tests are easy. Where I run into trouble filling in the table of effect sizes
is the Mahalanobis D as an effect size. I've included the table so you can see
what group's I'm comparing. I know there's a great function for filling in ?1
and ?2 : mahalanobis(x, center, cov, inverted=FALSE, ...) I need to turn the
sub groups scores for y (young), m (middle) and o (old) into clusters.
The problem is I lack the knowledge around cluster analysis of what goes into
the function for [x, center, & cov.] I have only a basic understanding of this
topic (a picture of a measured distance between two clusters on a graph). I
think I have to turn the data into a matrix but lack direction. Could someone
please use my data set or a similar one (a multivariate with at least 3 outcome
variables) and actually run this function (mahalanobis). Then please send me
your output from [R] starting from the data set all the way to the statistic.
PS I know the Mahalanobis D should be ?1=3.93 & ?2=3.04.
Ive read and reread the manual around mahalanobis() and have searched through
the list serve for information. The info is for people who already have a
grasp of how to implement this concept.
I am running the latest version of R on a windows 7 machine.
Effect Sizes
Contrasts| Dependent Variables
Friends Parents Strangers All
Young-Middle -1.8768797* -3.2842941* -1.1094004* ?1
Middle-Old 1.34900725* 1.54919532* -2.0107882* ?2
(sorry the column names and values dont line up)
Age Friend Agression Parent Agression Stranger Agression
y 8 7 8
y 5 6 8
y 6 3 7
y 5 5 7
m 15 13 10
m 13 11 9
m 12 12 9
m 18 10 7
o 11 11 10
o 10 4 12
o 12 9 12
o 9 8 14
y 13 7 7
y 9 5 10
y 11 4 4
y 15 3 4
m 14 12 8
m 10 15 11
m 12 11 8
m 10 9 9
o 10 8 11
o 13 11 13
o 9 8 12
o 7 9 16
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