How can I make the graph filled with the nodes and edges?

I found that it was good when there exist a lot of nodes and edges like more than 10 nodes and edges.However when only have 3 nodes and 2 edges the graph seems vacant,so I want to fill the graph with nodes and edges whenever how many nodes and edges.
How can I do , can any one help me?

You can add more nodes and links by adding data to the model. Remember to perform a transaction that surrounds all of the changes that you make.

I do not know anything about your application, so it is impossible to give specific advice.

now:

this seems vacant with a lot of space aroud the three nodes.

Expected:
When I enter a button the graph can be following :


the graph is full of the sreen.

Ah, so you aren’t talking about adding nodes and links, but making the existing nodes and links look larger.

You can increase the Diagram.Panel.Scale.