These bar charts illustrate interference, the consequence of the interaction between modular graphics and the grid of the screen. The grid serves as a sieve that selects singular values from the continuous function and eliminates the parts between.
Regular interference occurs in all continuous functions. This Demonstration shows the situation with simple exponential functions as examples. You can designate the exponent, the modulo value, and the unit of the base scale below. The upper scale shows the interference values along this scale.