Friezes from Function Graphs
This Demonstration shows simple friezes from function graphs. Three unit cells are shown.[more]
Example: For , the function plotted is
For functions we use parts of shifted ordinary functions (to avoid accidental symmetry): , , …, , , , ….
The mirror about the axis is obtained using and , and about the half-turn by using and .
The mirror about the axis is obtained using both graphs and filled to the axis.
 F. A. Farris, Creating Symmetry: The Artful Mathematics of Wallpaper Patterns, Princeton: Princeton University Press, 2015 pp. 52–53.