Show HN: A tool to visualize exponential sums

I'm not sure exactly what this is, but it's super interesting and fun to play with the equation to display moving plots.

The following produces some interestingly random results:

   f(x) = x/3 + tan(x/PI)

https://anvaka.github.io/e-sum/?code=x%2F3%20%2B%20tan%28x%2...