在Graphviz中使用子图时对齐节点

我想在Graphviz中使用子图时对齐节点

它在没有子图的绘图中工作得非常好。但当我引入子图时，节点发生了（意外的？）移动

下面是一个简单的例子

digraph My_test_without_subgraphs {

  graph [overlap = true, compound = true, rankdir = LR]

  node [shape = box, color = lightgrey, style = filled, fontcolor = black]
  T1 [label = 'my task 1']
  T2 [label = 'my task 2']
  T3 [label = 'my task 3']
  T4 [label = 'my task 4']

  T1 -> T3
  T2 -> T3
  T3 -> T4

}

digraph My_test_with_subgraphs {

  graph [overlap = true, compound = true, rankdir = LR]

  node [shape = box, color = lightgrey, style = filled, fontcolor = black]
  T1 [label = 'my task 1']
  T2 [label = 'my task 2']
  T3 [label = 'my task 3']
  T4 [label = 'my task 4']

  subgraph cluster1 {
  label = 'cluster 1'
  color = cornsilk
  style = filled
  T1 -> T3
  T2 -> T3
  }

  subgraph cluster2 {
    label = 'cluster 2'
    color = cornsilk
    style = filled
    T3 -> T4
  }
}

---

向第二个簇添加一个略小的边距，如下所示：

margin = 7.99

这就是诀窍

---

别问我为什么…

是的，保证金起作用。值本身并不重要，只要它是一个小于8的数字

顺便说一句，请使用“代替”，一些口译员，特别是在线编辑，会出现错误

digraph My_test_without_subgraphs {

  graph [overlap = true, compound = true, rankdir = LR]

  node [shape = box, color = lightgrey, style = filled, fontcolor = black]
  T1 [label = "my task 1"]
  T2 [label = "my task 2"]
  T3 [label = "my task 3"]
  T4 [label = "my task 4"]

  T1 -> T3
  T2 -> T3
  T3 -> T4

}

结果：

及

导致

---

谢谢。在这个简单的例子中效果很好，但在更复杂的绘图（三个子图，更多节点）中，这个技巧不起作用……你知道我们如何“推广”这个技巧吗？对不起，这是一个幸运的机会，不知道如何正确地做到这一点。

digraph My_test_with_subgraphs {

  graph [overlap = true, compound = true, rankdir = LR]

  node [shape = box, color = lightgrey, style = filled, fontcolor = black]
  T1 [label = "my task 1"]
  T2 [label = "my task 2"]
  T3 [label = "my task 3"]
  T4 [label = "my task 4"]

  subgraph cluster1 {
  label = "cluster 1"
  color = cornsilk
  style = filled
  T1 -> T3
  T2 -> T3
  }

  subgraph cluster2 {
    margin = 6
    label = "cluster 2"
    color = cornsilk
    style = filled
    T3 -> T4
  }
}