3D representation of the data ’MHD25’+’HD25’ (blue) and ’MHD50’+’HD50’ (orange) after the PCA step. The predicted clusters are marked with circles and triangles. The contribution of each PC is as follows: 73% for PC1, 15% for PC2, and 10% for PC3. As in Fig. 3, we can still clearly see two clusters. However, visually, PC3 does not allow more efficient separation of clusters. Thus, in this work, 2D visualisation was mainly used (only the two PCs).