Classification scheme of projections into classes. Classification of projections using (2 of the 3) Euler angles for viruses having Icosahedral symmetry like the herpes virus. Only an asymmetric triangle is needed in the case of an Icosahedrally symmetric virus instead of the whole plan in the case of an asymmetric object. Each rectangle represents a class of projections. The closest projection to the center of the rectangle, represents the center of the class. This figure represents the classification of 2600 projections into 300 classes.