How to influence layout of graph items?

Question

I am trying to visualize a simple Finite State Machine graph using Graphviz. The layout created by Graphviz is not completely to my liking. I was expecting a more compact result with shorter edges.

So far, I have tried using groups and changing the weights of edges, but not much luck. It is not clear to me why Graphviz draws the graph the way it does and how to adjust its algorithm to my liking. Are there any parameters I can set to achieve that? Or should I use another command than dot? I tried neato, but the result looked completely messed up and again, I do not really understand what I am doing...

This is my best result so far:

Finite State Machine, best result so far

Trying to visualize a better lay-out than this, I think the graph would look nicer if the red boxes were aligned differently, more compact for example like indicated by the arrows in this picture:

Finite State Machine, imagined better result

I used dot to create the graph and he source code is as follows:

  1 digraph JobStateDiagram
  2 {
  3   rankdir=LR;
  4   size="8,5";
  5 
  6   node  [style="rounded,filled,bold", shape=box, fixedsize=true, width=1.3, fontname="Arial"];
  7   Created   [fillcolor=black, shape=circle, label="", width=0.25];
  8   Destroyed [fillcolor=black, shape=doublecircle, label="", width=0.3];
  9   Empty     [fillcolor="#a0ffa0"];
 10   Announced [fillcolor="#a0ffa0"];
 11   Assigned  [fillcolor="#a0ffa0"];
 12   Working   [fillcolor="#a0ffa0"];
 13   Ready     [fillcolor="#a0ffa0"];
 14   TimedOut  [fillcolor="#ffa0a0"];
 15   Failed    [fillcolor="#ffa0a0"];
 16 
 17   {
 18     rank=source; Created Destroyed;
 19   }
 20 
 21   edge  [style=bold, fontname="Arial" weight=2]
 22   Empty     -> Announced [ label="announce"   ];
 23   Announced -> Assigned  [ label="assign"     ];
 24   Assigned  -> Working   [ label="start"      ];
 25   Working   -> Ready     [ label="finish"     ];
 26   Ready     -> Empty     [ label="revoke"     ];
 27 
 28   edge  [fontname="Arial" color="#aaaaaa" weight=1]
 29   Announced -> TimedOut  [ label="timeout"    ];
 30   Assigned  -> TimedOut  [ label="timeout"    ];
 31   Working   -> TimedOut  [ label="timeout"    ];
 32   Working   -> Failed    [ label="error"      ];
 33   TimedOut  -> Announced [ label="announce"   ];
 34   TimedOut  -> Empty     [ label="revoke"     ];
 35   Failed    -> Announced [ label="announce"   ];
 36   Failed    -> Empty     [ label="revoke"     ];
 37 
 38   edge  [style=bold, fontname="Arial" weight=1]
 39   Created   -> Empty     [ label="initialize" ];
 40   Empty     -> Destroyed [ label="finalize"   ];
 41   Announced -> Empty     [ label="revoke"     ];
 42   Assigned  -> Empty     [ label="revoke"     ];
 43   Working   -> Empty     [ label="revoke"     ];
 44 }

Also, anybody please let me know if I do any strange things in the Graphviz file above -- any feedback is appreciated.

Update:

More experimenting and trying some suggestions like ports, given by user marapet, have increased my confusion... For example, in the picture below, why does dot choose to draw these strange detours for Working->Failed and Failed->Announced, as opposed to straighter lines?

Graph with strange long edges

user_5259354 · Answer

Although this is a very old question, I had similar problem and would like to share my result. Besides the "weight", "rank=same" tricks, I just found these methods can be used to adjust the layout result:

dir=back
add more edges or nodes and set style=invis

When it comes to this particular graph in the question, actually rank=same and weight would do the main job and style=invis can do some fine tuning. So by adding these lines

 {
  rank=same;Announced;Failed;
 }
 {
  rank=same;Assigned;TimedOut;
 }

to the file and adding weight=1 to the 'Ready to Empty' edge, and with some invisible edges to fine tune the spaces I got this:

The complete graph dot source:

digraph JobStateDiagram
{
  rankdir=LR;
  size="8,5";

  node  [style="rounded,filled,bold", shape=box, fixedsize=true, width=1.3, fontname="Arial"];
  Created   [fillcolor=black, shape=circle, label="", width=0.25];
  Destroyed [fillcolor=black, shape=doublecircle, label="", width=0.3];
  Empty     [fillcolor="#a0ffa0"];
  Announced [fillcolor="#a0ffa0"];
  Assigned  [fillcolor="#a0ffa0"];
  Working   [fillcolor="#a0ffa0"];
  Ready     [fillcolor="#a0ffa0"];
  TimedOut  [fillcolor="#ffa0a0"];
  Failed    [fillcolor="#ffa0a0"];

  {
    rank=source; Created Destroyed;
  }
  {
    rank=same;Announced;Failed; #change here
  }
  {
    rank=same;Assigned;TimedOut; #change here
  }

  edge  [style=bold, fontname="Arial" weight=20] #change here
  Empty     -> Announced [ label="announce"   ];
  Announced -> Assigned  [ label="assign"     ];
  Assigned  -> Working   [ label="start"      ];
  Working   -> Ready     [ label="finish"     ];
  Ready     -> Empty     [ label="revoke" weight=1 ]; #change here

  edge  [fontname="Arial" color="#aaaaaa" weight=2] #change here
  Announced -> TimedOut  [ label="timeout"    ];
  Assigned  -> TimedOut  [ label="timeout" weight=1]; #change here
  Working   -> TimedOut  [ label="timeout"    ];
  Working   -> Failed    [ label="error"      ];
  TimedOut  -> Announced [ label="announce"   ];
  TimedOut  -> Empty     [ label="revoke"     ];
  Failed    -> Announced [ label="announce"   ];
  Failed    -> Empty     [ label="revoke"     ];

  edge  [style=bold, fontname="Arial" weight=1]
  Created   -> Empty     [ label="initialize" ];
  Empty     -> Destroyed [ label="finalize"   ];
  Announced -> Empty     [ label="revoke"     ];
  Assigned  -> Empty     [ label="revoke"     ];
  Working   -> Empty     [ label="revoke"     ];
  
  Assigned  -> Working   [ label="start"  style=invis     ]; #change here 
  Assigned  -> Working   [ label="start"  style=invis     ]; #change here 
}

Update: instead of putting 'Failed' and 'Announced' at the same rank, putting 'Failed', 'Assigned' and 'TimedOut' the same rank might produce a better result like below, which IMO better illustrates the similarity and difference between Failed and TimedOut. (You have to remove the invis edges though to get the graph below)

How to influence layout of graph items?

2 Answers