Performing partial layout when adding nodes

I was wondering if it is possible to add new nodes and links to a diagram following the conventions of a layered layout, but without performing a full layout function. The point being that I do not want any existing nodes to be moved. The new nodes will have at least 1 link to an existing node.

The basic problem I have is that if I add a collection of linked nodes to the diagram, they are placed on top of existing nodes and the resulting layout does not look layered. I do not want to perform a full layout of the entire diagram because I want the existing nodes to remain stationary. The resulting layout does not need to be optimum of course.

The best solution I have come up with is to place the new nodes into a network, generate a sub layout, then try to position the sub layout somewhere on the diagram that “has enough space” near the existing nodes they are connected with.


You’re right, we don’t have a facility for doing a partial layered layout that is relative to existing nodes. Given the way layered layout works, it sort of doesn’t make sense… but I do see why you need this.

Force directed layout lets you "Fix" some nodes so they don't get moved. I'm wondering if you could use that to do the positioning after the layered layout of the new nodes. (create a big "node" that represents the entire new subgraph, then do a force directed layout of that against the rest of the diagram, all "fixed" to their spots. This might work really well some times, but I'm not sure the results would predictable.