Eigenimages-Symmetry. (a) A model dataset with 4-fold symmetry. (b) Eigenimages from that dataset. Eigenvectors 2 and 3 have clear 4-fold symmetry and are rotated with respect to one another by 22.5° degrees. (c) Tetrameric α-latrotoxin raw images (top row), class averages (middle row), and eigenimages (bottom row). The eigenimages showing 4-fold and pseudo 8-fold symmetry are shown with numbers. (d) Class averages of top views from the connector of bacteriophage SPP1 are shown in the top panel. Classes where the symmetry is visible are highlighted with yellow circles. The eigenimages are in the bottom panel. Eigenimage 1 represents the total sum of the data and the 12-fold symmetry is revealed in eigenimages 2 and 3.