How can I merge nodes together?

Question

I have a graph where I have realized that some nodes are redundant with each other, and I'd like to replace the redundant nodes with a single node whose edges are the union of the original nodes' edges.

For example, suppose my graph has A->B->C, B->F, A->D->C, D->E. I've decided that I think B and D are redundant. I'd like to select B and D and perform a merge operation to replace B and D with a new node BD such that the resulting graph is A->BD->C, BD->F, BD->E.

Does yEd have such a feature?

Answer 1

Yes, you can do that in yEd with the following apporach:

1. Select nodes B and D.
2. Create a group node that contains B and D using "Grouping" -> "Group".
3. Close the new group node.
4. Make sure the closed group is selected and it is the only selected node.
5. Choose a node style template for normal (i.e. non-group) nodes in yEd's palette.
6. Right-click the chosen template to open its context menu and choose "Apply" or "Apply Type".

The last step will convert the closed group node into a normal node.

You could even stop after step 3. Closed group nodes behave very similar to normal nodes and while they do not support as many different styles as normal nodes, they can be opened again and thus provide you with access to the originally "merged" nodes.