5
$\begingroup$

Is it possible to combine two edges into one with a double arrow?

For example:

GraphPlot[{1 -> 2, 2 -> 1}, VertexLabeling -> True, DirectedEdges -> True]

results something like

enter image description here

Is it possible to change it to something like

enter image description here

without using the drawing tool to edit the graphics directly?

Improve this question
$\endgroup$
2
  • $\begingroup$ Which version of Mathematica are you using? $\endgroup$ Commented Apr 20, 2013 at 19:02
  • $\begingroup$ version 8 on Mac. $\endgroup$ Commented Apr 20, 2013 at 19:05

2 Answers 2

Reset to default
3
$\begingroup$

This is a hack, but it'll work with GraphPlot:

GraphPlot[{1 -> 2, 2 -> 1, 1 -> 3, 3 -> 2}, MultiedgeStyle -> .001, DirectedEdges -> True]

enter image description here

Improve this answer
$\endgroup$
3
  • $\begingroup$ Thanks, that works. But the combined line seems slightly thicker than the others, do you know how to deal with that? $\endgroup$ Commented Apr 20, 2013 at 19:23
  • $\begingroup$ @user0501 Unfortunately no. I'd have to search the docs more for that and right now I do not have the time. Also, ideally there should be a solution for Graph objects, not just GraphPlot. My answer is by no means complete. $\endgroup$ Commented Apr 20, 2013 at 19:35
  • $\begingroup$ @user0501 I'm trying to do the same thing with LayeredGraphPlot with little success, so I might try Szabolcs solution. However, from your comment, to deal with the thicker double arrow, could you add something in such that if a rule and its inverse are both found, to reduce the thickness of each resulting edge by 50%? $\endgroup$ Commented Jun 12, 2015 at 19:47
2
$\begingroup$

The option settings False and None are not listed among documented typical settings, but both MultiedgeStyle -> False and MultiedgeStyle -> None give the desired result.

GraphPlot[{1 -> 2, 2 -> 1}, MultiedgeStyle -> False, DirectedEdges -> True, VertexLabeling -> True]

enter image description here

GraphPlot[{1 -> 2, 2 -> 1, 1 -> 3, 3 -> 2}, MultiedgeStyle -> False, DirectedEdges -> True, VertexLabeling -> True]

enter image description here

GraphPlot[{1 -> 2, 2 -> 1, 1 -> 3, 3 -> 2}, MultiedgeStyle -> None, DirectedEdges -> True, VertexLabeling -> True]

enter image description here

Notes:

  • This works in version 9 (windows 10) and in version 11.2 on Wolfram Cloud.
  • After major updates in version 12.0, GraphPlot usage/options changed completely. Use GraphComputation`GraphPlotLegacy instead of GraphPlot for the code above to work.
Improve this answer
$\endgroup$

Start asking to get answers

Find the answer to your question by asking.

Ask question

Explore related questions

See similar questions with these tags.