In the past to describe symmetry and the plane groups, I drew patterns in the dotted form which are shown below:
http://www.ikolam.com/node/3314
http://www.ikolam.com/node/3263
http://www.ikolam.com/node/3262
Suddenly, I got an idea yesterday, why not use numbers for the various rotation axes. It is so easy to understand. Accordingly the numbers 1 (for 360 deg rotation or no symmetry), 2 (for 180 deg rotation), 3 (for 120 deg rotation), 4 (for 90 deg rotation) and 6 (for 60 deg rotation) were used. Where a mirror symmetry is present with these rotations, the mirror images of the numbers were used. For only the mirror symmetry, the letter m was used. If there is interest, I will upload magnified images. Enjoy!
Regards! - mOhana
