I have the following code:
digraph g {
graph [rankdir=\"LR\" ,compound=\"true\" ];
subgraph cluster0 {
graph [label=\"Ready\\n\\nAllowed Purchaser Op
I think what you are looking for (as Emden points out) are indeed the nodesep and ranksep attributes.
graph [nodesep=6, ranksep=4];
The result would be:
Clusters are derived objects; their layout depends solely on the nodes contained in them. Thus, to alter the cluster spacing, you need to alter the node spacing. Try setting the ranksep and nodesep attributes to larger values.