PCA of the distances between the different descriptor sets. Shown are the first two components (A). T-scales, ST-scales and MSWHIM, and to a lesser extent Z-Scales (3) cluster together, as do FASGAI, VHSE, ProtFP (PCA3), and Z-Scales (5). Furthermore Z-Scales (Binned) and BLOSUM are nearest neigbors. ProtFP (PCA5) and (8) are seen to cluster away from the others. Furthermore. (B) When the first three PCs are displayed Z-scales (5) and ProtFP (PCA3) are seen to be distant from their cluster in the first two PCs.