How can I add a small circle or square at the intersection of edges?

Question

I am making a decision tree for a healthcare cost-effectiveness model. I would like to display a small circle at the intersection of edges, to illustrate that these branches are "chance/event nodes". I also want to be able to do the same with a small square to indicate a "decision node". (Quotes on these because node means something slightly different than in yEd-- I'm talking about the point at which multiple options split off).

In my example, I have a node "Eligible for testing" that then has edges going to "offered testing" and "not offered testing". I want there to be a small black circle right on top of the T where the edges split coming out of "Eligible for testing".

Answer 1

Well, you could model your chance/event and decision "nodes" as actual nodes. (This is essentially how it is done in flow charts.) This ensures the visualization of these special nodes is always at the correct position.

Other than that you could probably place edge labels with icons at the appropriate positions. However, this approach will require you to manually correct the position of these labels whenever the paths of corresponding edges changes.