A fundamental concept I reminded in the article I wrote shamefully some very much time ago, is that different charts correspond to different analysis needs and reproduce different views of a two-way table. While at the time I have discussed some charts translating the table by horizontal or vertical sections, that is, by rows or columns, here I’m going to introduce a chart beloging to the group of symmetrical representations, those which do not change transposing the table and hence which deal with rows and columns on the same level either.
The following figures show four examples of symmetrical chart types for two-way tables: the flowchart, the heatmap, the fluctuation diagram and the matrix bubble chart. The last three ones are the simplest in the sense that they reproduce the table grid substituting each cell value by a rectangle or circle with color (the former) or area (the latter) proportional to them.