My first year classes are doing Introduction to waves activity which involves building a wave simulation in Geogebra. I thought I'd refresh my skills by trying to build a 2D version. I did it by using a sequence in a sequence to define a grid of points, a sin function gives the oscillation in the y component. To get the circular wave the phase of the oscillation is dependent on the distance from the centre which is calculated using Pythagoras. Lost?

Here is the code: