Cluster analysis results for low redshift galaxies. Superimposed to the points, as in Fig. 5, are the isodenses of the points calculated via kernel smoothing in PC1-PC2 and PC1-PC3 planes. The curved lines represent the projected isoprobability curves. Clusters and green valley objects appear more scattered across the planes because of effects of projection from the four-dimensional PCA to the two dimensions of the plot.