Use TreePlot to create organization or flow charts?

Questions
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1

Hi everyone,
I am wondering whether there is a way to use TreePlot to create organization or flow charts. Here is a default tree plot from the Wolfram documentation.

TreePlot[{1 -> 4, 1 -> 6, 1 -> 8, 2 -> 6, 3 -> 8, 4 -> 5, 
  7 -> 8}, Top, VertexLabeling -> True]

As intended, the branches radiate out from the centre of each vertex. In an organization or flow chart, the branches come out of each vertex at right angles to the vertex (example attached and hopefully embedded in this post).

OrganizationChart.png
OrganizationChart.png1650×1275 39.4 KB

Any thoughts?

Greg

2

I can’t see your image, but I guess you want something like:

ClearAll[func]
func[{ri_,rj_},___]:=If[FreeQ[ri-rj,0.], Line[{ri,{rj[[1]],ri[[2]]},rj}],Line[{ri,rj}]]
TreePlot[{1->4,1->6,1->8,2->6,3->8,4->5,7->8},Top,VertexLabeling->True,EdgeRenderingFunction->func]

ScreenShot2017-03-30at18.14.35.png
ScreenShot2017-03-30at18.14.35.png666×574 6.06 KB

3

Hi Sander,

The image is also in an attachment. Thanks for your suggestion. It’s pretty darn close. I’m going to study your code.

Regards,

Gregory

4

I don’t understand because I did upload a PNG. In any case, if you do a Google search for organization chart and check out the images, it will be clear.

Thanks again,

Gregory

5

Aah ok I see it now:

ClearAll[func]
func[{ri_,rj_},___]:=If[FreeQ[ri-rj,0.],Line[{ri,{ri[[1]],(ri[[2]]+rj[[2]])/2},{rj[[1]],(ri[[2]]+rj[[2]])/2},rj}],Line[{ri,rj}]]
TreePlot[{1->4,1->6,1->8,2->6,3->8,4->5,7->8},Top,VertexLabeling->True,EdgeRenderingFunction->func]

ScreenShot2017-03-30at21.17.20.png
ScreenShot2017-03-30at21.17.20.png672×558 6.06 KB

6

Hi Sander,

This is so cool. Just what the doctor ordered. It will take me a little time to study and understand your edge function, but it looks like the FreeQ[…,0.] condition ensures that the branches travel at right angles to the vertices and the division by 2 draws the horizontal lines. I never would have thought of this.

Thanks once again,

Greg

7

Strictly the FreeQ condition is not necessary, it will just save a bit of memory… visually it will look the same…

8

Hi, @Sander Huisman. This is fantastic. I’d like to add arrows using this code. I tried adding DirectedEdges->True with no avail. Any suggestions? Thanks!

9

That is because my own EdgeRenderingFunction ignores this DirectedEdges option. I’m fairly certain that if you change Line to Arrow (2 times) it should work…

10

Thank you so much. That worked.