How to get trees more balanced?

[jiyinyiyong]

it looks balanced when the tree itself is actually balanced:

but it’s being skewed If I add an 6 in this way:

can I force graphviz to lay out in a balanced way?

[steveroush]

Would you explain more about what balanced means in this case. Maybe just a pencil sketch.

[scnorth]

Maybe a seemingly obvious brute force algorithm would suffice here? I’m not sure what’s considered state of the art now, but we need to handle arbitrary fanout, and variable width nodes.

[jiyinyiyong]

something like this:

maybe I should call it “symmetric”, despite how many children a node has?

[steveroush]

Simplest (?) way is to define invisible nodes that are used to “fill out” the tree to make it symmetric

digraph T{
  node [shape=circle width=.6]
  10 -> { 85 30 7}
  85 -> { 31 15 40}
  30 -> {63 1 "15a" [label="15"]}

    7 // define visible node
    node [label="" style=invis]
    edge [style=invis]
    7 -> {dummy1 dummy2 dummy3 }
}

Giving: