The first two PC loadings against each other are shown in Figure 1 . Because the PCA is invariant to the mirroring through the origin, the data shown here indicate that there is a significant correlation between LigScore1 and PLP1. Likewise, the correlation between G_Score and D_Score in relation to the data is unambiguous and significant. There is no need to measure and evaluate all of the variables to achieve the same characterization in further studies. It is sufficient to measure one variable per group.