top-down subgraphs, left-right inside subgraphs

Question

I'd like to have my graph looks like this:

But I can only get this:

The problem is, rankdir does not work in subgraph. So, how to emulate it?

The code:

digraph G {
    node [shape = circle]
    0 [style = invis]

    0 -> "0A"

    subgraph clusterA {
        label=A
        "0A"
        "1A"
        "2A" -> "0A" [label=•]
    }

    subgraph clusterB {
        label=B
        "0B"
        "1B"
        "2B" -> "0B" [label=•]
    }

        subgraph clusterC {
        label=C
        "0C"
        "1C"
        "2C" -> "0C" [label=•]
    }

    subgraph clusterD {
        label=D
        "0D"
        "1D"
        "2D" -> "0D" [label=•]
    }

    subgraph clusterE {
        label=E
        "0E"
        "1E"
        "2E" -> "0E" [label=•]
    }

    subgraph clusterF {
        label=F
            {node [shape = doublecircle] "0F" "1F"}
        "2F" -> "0F" [label=•]
    }

    "0A" -> "1B" [label=a]
    "1A" -> "2B" [label=a]
    "0B" -> "1C" [label=b]
    "1B" -> "2C" [label=b]
    "0C" -> "1D" [label=c]
    "1C" -> "2D" [label=c]
    "0D" -> "1E" [label=d]
    "1D" -> "2E" [label=d]
    "0E" -> "1F" [label=e]
    "1E" -> "2F" [label=e]
}

https://gitlab.com/graphviz/graphviz/issues/887 – morpheus Dec 29 '19 at 22:18 — morpheus, Dec 29 '19 at 22:18

score 68 · Accepted Answer · edited Jul 11 '17 at 20:47

Reproducing particular graph layouts usually can be achieved with:

Invisible nodes and edges
rank constraints

Here's how I reproduced your graph - or at least a part of it:

digraph g {
    rankdir="LR";
    node[shape = circle, fontsize=14];
    fontsize=18;
    labeljust="l";

    edge[style=invis, fontsize=12];

    { rank=same;
        0 [style = invis];
        01 [style = invis];
        02 [style=invis];
        0 -> 01 -> 02;
    }

    subgraph clusterA {
        "0A" -> "1A" -> "2A";
        "2A" -> "0A" [label=".", constraint=false, style=solid];
        label="A";
    }

    subgraph clusterB {
        "0B" -> "1B" -> "2B";
        "2B" -> "0B" [label=".", constraint=false, style=solid];
        label="B";
    }

    subgraph clusterC {
        "0C" -> "1C" -> "2C";
        "2C" -> "0C" [label=".", constraint=false, style=solid];
        label="C";
    }

    0 -> "0A"[style=solid];
    01 -> "0B"[style=invis];
    02 -> "0C"[style=invis];

    // edges between clusters
    edge[constraint=false, style=solid];
    "0A" -> "1B" [label=a]
    "1A" -> "2B" [label=a]
    "0B" -> "1C" [label=b]
    "1B" -> "2C" [label=b]
}

This solution is not very intuitive. A couple of points to achieve this:

I chose rankdir="LR" which resulted in nicer edges than TB, though it does not really correspond with the direction of the graph
Invisible nodes and edges are use for the top rank nodes (0, 01, 02) in order to have the clusters align left.
The (invisible) top nodes are forced to the same rank and are linked by invisible edges - this will ensure that the clusters linked to each node appear in the correct order.

The result is:

graphviz output

It seems that the algorithm has changed. I get a weird 0C when I paste your solution in viz.js — nachocab, Dec 06 '18 at 12:02

Thomas Luechtefeld · Answer 2 · 2022-07-19T12:55:52.913

5

It looks like rank=same might be a cleaner solution. Take a look at Placing clusters on the same rank in Graphviz.

You can also use 'constraint=false' and invisible edges to carefully control node rank. This is basically the same answer as the above.

digraph G {
    newrank=true; // rank without respect to cluster
    rankdir="LR"; 
    node [shape = circle]
    
    subgraph clusterA {
        a0 -> a1 -> a2 [style = invis] // set node order in cluster
        a2 -> a0 [constraint=false] //don't use this edge for ranking
    }

    subgraph clusterB {
        b0 -> b1 -> b2 [style = invis]
        b2 -> b0  [constraint=false]
    }
    
    a0 -> b1 [constraint=false]
    a1 -> b2 [constraint=false]
    
}

edited Jul 19 '22 at 12:55

answered Jun 28 '21 at 02:29

Thomas Luechtefeld

1,316
15
23

I don't think that would help since the clusters aren't placed on the same rank. – Björn Lindqvist Jul 18 '22 at 02:12
A very clean answer, also expandable without problems, I tried this up to 5 boxes. – Wolf Aug 30 '22 at 10:07
Works the same without `newrank=true;`. – Wolf Aug 30 '22 at 10:24

score 2 · Answer 3 · answered Dec 06 '18 at 12:09

An update on @marapet's answer using group

digraph g {
rankdir="LR";
node[shape = circle, fontsize=14];
fontsize=18;
labeljust="l";

edge[style=invis, fontsize=12];

{ rank=same;
    0 [group=a style = invis];
    01 [style = invis];
    02 [group=b style=invis];
    0 -> 01 -> 02;
}

subgraph clusterA {
    "0A" [group=a]
    "0A" -> "1A" -> "2A";
    "2A" -> "0A" [label=".", constraint=false, style=solid];
    label="A";
}

subgraph clusterB {
    "0B" -> "1B" -> "2B";
    "2B" -> "0B" [label=".", constraint=false, style=solid];
    label="B";
}

subgraph clusterC {
    "0C" [group=b]
    "1C" [group=b]
    "0C" -> "1C" -> "2C";
    "2C" -> "0C" [label=".", constraint=false, style=solid];
    label="C";
}

0 -> "0A"[style=solid];
01 -> "0B"[style=invis];
02 -> "0C"[style=invis];

// edges between clusters
edge[constraint=false, style=solid];
"0A" -> "1B" [label=a]
"1A" -> "2B" [label=a]
"0B" -> "1C" [label=b]
"1B" -> "2C" [label=b]
}

score 2 · Answer 4 · answered Oct 16 '11 at 16:24

Using constraint=false should get the nodes in your subgraphs to turn out the way you want http://www.graphviz.org/doc/info/attrs.html#d:constraint

subgraph clusterB {
    label=B
    "0B"
    "1B"
    "2B" -> "0B" [constraint=false label=•]
}

After that you'll find that your subgraphs don't line up with each other the way you want. Something like this could resolve that.

"0A" -> "0B" -> "0C" -> "0D" -> "0E" [weight=999 style=invis];

score 1 · Answer 5 · answered Apr 26 '19 at 17:40

rankdir doesn't work directly in the subgraph, but if you add another set of curly braces - whatever that's called - rankdir works. See below. Then, obviously you need more tricks to restore the alignment and ordering you're after.

digraph G {
    node [shape = circle]
    0 [style = invis]

    0 -> "0A"

    subgraph clusterA {
        label=A
        {
            rank=same
            "0A"
            "1A"
            "2A" -> "0A" [label=•]
        }
    }

    subgraph clusterB {
        label=B
        {
            rank=same
            "0B"
            "1B"
            "2B" -> "0B" [label=•]
        }
    }

    subgraph clusterC {
        label=C
        {
            rank=same
            "0C"
            "1C"
            "2C" -> "0C" [label=•]
        }
    }

    subgraph clusterD {
        label=D
        {
            rank=same
            "0D"
            "1D"
            "2D" -> "0D" [label=•]
        }
    }

    subgraph clusterE {
        label=E
        {
            rank=same
            "0E"
            "1E"
            "2E" -> "0E" [label=•]
        }
    }

    subgraph clusterF {
        label=F
        {
            rank=same
            {node [shape = doublecircle] "0F" "1F"}
            "2F" -> "0F" [label=•]
        }
    }

    "0A" -> "1B" [label=a]
    "1A" -> "2B" [label=a]
    "0B" -> "1C" [label=b]
    "1B" -> "2C" [label=b]
    "0C" -> "1D" [label=c]
    "1C" -> "2D" [label=c]
    "0D" -> "1E" [label=d]
    "1D" -> "2E" [label=d]
    "0E" -> "1F" [label=e]
    "1E" -> "2F" [label=e]
}

This worked very well, and much simpler to read than the other answers. — CodeMonkey, Jul 04 '19 at 10:16
You're not using rankdir, are you? It seems you're using `rank=same` instead, which breaks the graph: the order of the nodes in the clusters changes. — Clément, Oct 24 '20 at 20:36

top-down subgraphs, left-right inside subgraphs

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