Fig. 5.

Non graphical solutions to the Cattell subjective scree test. EVs as major factor extraction decision criteria. An acceleration factor (af) and the optimal coordinates index (oc). The af indicates where the elbow of the scree plot appears. It corresponds to the acceleration of the curve. The oc are the extrapolated coordinates of the previous eigenvalue that allow the observed eigenvalue to go beyond this extrapolation (made by a linear regression using the last eigenvalue coordinates and the k + 1 eigenvalue coordinates) (Raichem and Magis 2011). See also Electronic Supplementary Material Table S3