alignment - 在Graphviz中垂直对齐连接子图的节点

Question

我向 Dot 提供以下输入:

digraph G {
  subgraph cluster1 {
    fontsize = 20;
    label = "Group 1";
    A -> B -> C -> D;
    style = "dashed";
  }

  subgraph {
    O [shape=box];
  }

  subgraph cluster2 {
    fontsize = 20;
    label = "Group 2";
    Z -> Y -> X -> W [dir=back];
    style = "dashed";
  }

  D -> O [constraint=false];
  W -> O [constraint=false, dir=back];
}

它产生:

如何对齐节点 O 使其与 D 和 W 具有相同的等级？也就是说，一个图形看起来像:

A   Z
|   |
B   Y
|   |
C   X
|   |
D-O-W

添加

 { rank=same; D; O; W; }

产生错误

Warning: D was already in a rankset, ignored in cluster G
Warning: W was already in a rankset, ignored in cluster G

我想我可以通过向 O 的子图中添加不可见的节点和边来破解它，但我想知道我是否错过了一些点魔法。

Answer 1

您可以使用 rankdir=LR 的方法，并将 constraint=false 用于集群内的边缘:

digraph G {
  rankdir=LR;

  subgraph cluster1 {
    fontsize = 20;
    label = "Group 1";
    rank=same;
    A -> B -> C -> D [constraint=false];
    style = "dashed";
  }

  subgraph cluster2 {
    fontsize = 20;
    label = "Group 2";
    rank=same;
    Z -> Y -> X -> W [dir=back, constraint=false];
    style = "dashed";
  }

  O [shape=box];
  D -> O -> W;
}

这不是点魔法:-)，但它实现了这一点:

使用隐形节点进行黑客攻击也有效:

digraph G {
  subgraph cluster1 {
    fontsize = 20;
    label = "Group 1";
    A -> B -> C -> D;
    style = "dashed";
  }

  subgraph {
    O1[style=invis];
    O2[style=invis];
    O3[style=invis];
    O [shape=box];

    O1 -> O2 -> O3 -> O [style=invis];
  }

  subgraph cluster2 {
    fontsize = 20;
    label = "Group 2";
    Z -> Y -> X -> W [dir=back];
    style = "dashed";
  }

  edge[constraint=false];
  D -> O -> W;
}

结果几乎相同: