Arc graph layout in GraphViz

dot, graphviz

Solution

As I don't have enough reputation to add a comment, I post some suggestion here. The following code solve the problem of force nodes to stand in one line.

digraph "test-graph" {
    graph [rankdir=LR]
    node[shape=circle, color=lightblue,label="",style=filled,width=0.3];
    edge[arrowhead=none,splines=line];
    1->2;
    2->3;
    edge[splines=curved];
    1->3[constraint=false];
}

but don't have power for semi-circle edge. You can try other tools,such as Tikz.

Problem

Original source