This is pretty interesting. I've seen a similar technique for handling a single time series when the number of data points far exceeds the number of pixels, doi

This is pretty interesting. I've seen a similar technique for handling a single time series when the number of data points far exceeds the number of pixels, doing a two-dimensional histogram rather than connecting subsequent dots with line segments. I hadn't thought about how to do that for the case of having an extremely large number of time series overlaid on each other. This approach seems to produce results similar to what you'd see on an oscilloscope or an eye diagram.