How do I put N of the overlay variable onto a graph?
One of the data visualisations I am routinely producing is a set of X/Y data grouped by categorical variables in two dimensions to produce a square array of plots: see attached example. I further Overlay the X/Y data by an observation ID in order to connect all the data points from one observation with a line (placing another variable into the Color axis in order to keep the resulting plot readabl...