kieran healy share some code An example of a color-coded map where each region is given a circle in proportion to its population. He calls these „Dorling cartograms.“ This sounds a bit mysterious to me, but I understand there are no easy words to explain this. It is clear from the photo,
I wrote to Kieran and asked if he could create a graph without bullets around each point to make the graph easier to read.
he replied:
Yes, it's easy to do. Just give various parameters to geom_sf(). Specifically, we set the line width to 0 so that no border is drawn on the circle. So use geom_sf(linewidth=0) instead of geom_sf(color=“gray30”) etc. But I don't think this actually makes it easier to read on white, off-white, or light gray backgrounds.
The circle border does a great deal to help you visually recognize where the circle actually is as a separate element. It is possible to make the border less noticeable and still make it work.
In this version, the circle border is only *very slightly* darker gray than the background, but it's still a big difference.
Finally, you can also remove the circle border and make the background very dark like this:
That's not bad, but the problem is that the dark orange color doesn't display properly, especially in smaller counties where the percentage of black is very high. This works better with one of the other palettes.