Spacing between clusters

[pitosalas]

I am trying to make my graph pretty. I am using subclusters fairly extensively. The result I am getting is correct but could be prettier. Can I create more space between the subclusters?

[steveroush]

Indirectly. Look at the margin attribute (margin | Graphviz) and also consider nesting clusters - possibly with peripheries=0

digraph D{
  rankdir=LR
  subgraph clusterA{
    margin=55  //points
    a1->a2->a3
  }
  subgraph clusterB{
    margin=15  //points
    b1->b2->b3
  }
  subgraph clusterC{
    margin=55  //points
    subgraph clusterD1{
        margin=55  //points
	peripheries=0
    subgraph clusterD2{
        margin=55  //points
	peripheries=0
    subgraph clusterD5{
      margin=10  //points
      subgraph clusterE{
        peripheries=1
        margin=55  //points
        e1->e2->e3
      }
      d1->d2->d3
    }
    }
    }
  }
}

Giving: