I'm pretty new to working with graphs but I'm looking at using them to create the world map for our game (a text mud with rooms/nodes and paths/edges between rooms). There are a number of interesting small-world generators, for example Watts-Strogatz (http://en.wikipedia.org/wiki/Watts_and_Strogatz_model) that I'd like to combine.
My question is how to combine different generators. All the rooms will have coordinates in an XY plane (the rooms themselves won't have real dimensions). I can easily generate a graph, and then laying it out I can work out the XY coordinates of its nodes. But then I'd like to generate a new graph and connect at least one of its nodes to a node on the previous graph.
My first idea is to figure out the XY bounding box of a graph, and use that to place it in the larger XY plane next to the previous graph (kind of tiling the graphs). Are there other methods I should be aware of?