3D representation of the feature matrix X. Broadly, two categories are noticeable. The first group refers to the zPDFs with high dispersion, large z_MAP peak and low probability P(z_MAP|D, I) that can be assimilated to multimodal PDFs or platykurtic unimodal PDFs. The second group characterizes the zPDFs with medium-to-low dispersion, narrow z_MAP peak and high P(z_MAP|D, I) that depict strongly peaked unimodal PDFs.