graphvizneato

Increase curvature of connecting arcs

Consider:

digraph D {
    0[pos="0,0!"]
    1[pos="0,5!"]
    0 -> 1[label=0.25]
    1 -> 0[label=0.50]
}

Rendered under neato engine, this gives:

enter image description here

Is there a way to increase/control the curvature of the connecting arcs so that the rendering is something like the hand-drawn annotations below:

enter image description here

Edited to add: While I don't have to stick with neato, it is important in my application that the node pos coordinate values be upheld.

Solution

  • [there may be better ways, but edges are pretty hard to wrangle]
    This solution requires neato -n (see https://graphviz.org/faq/#FaqDotWithNodeCoords) and (https://graphviz.org/docs/attrs/pos/)
    Different versions of neato seem to produce different results when previous answer is input. This input file should work with older & newer versions of neato.

    digraph D {
    // next  lines from the Graphviz FAQ
    overlap=false
    splines=true
    
    0[pos="0,0!"]
    1[pos="0,5!"] 
    // stick an invisible node in the middle, to force the edges out
    half [pos="0,2.5!" width=1.1 height=1  style=invis]  
    0:nw -> 1:sw [label=0.25]
    1:se -> 0:ne [label=0.50]
}

    Giving:
    enter image description here