Hi, I use packages "momocs" and "ade4" to dertermine morphometry of woodpeckers' cavities entrances. I have few questions about the PCA (non-normalized) (see image enclosed) :
1) *What do show the confidence ellipses ?* Some papers say that ellipses include 95 % of the data, but it seems to be less here... Moreover, I can choose the size of the ellipses with "cellipse" (ex : cellipse=1), but what does it means ? 2) What does mean "d=50" (in the top-right corner) ? 3) What do mean each axis of the PCA ? Wikipedia say "Each axis on a PCA plot is an eigenvector of the covariance matrix of shape variables." But it's not really clear for me... What is the axis units ? Thanks for your help :-) VB
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