dot - Graphviz Dot 将节点放置在子图中，即使它是在其他地方定义的

Question

我正在尝试为家庭作业问题制作一个点脚本生成器，它进展顺利，除了我有这个问题，其中一些未在子图中定义的节点被放置在其中。例如下面的点脚本：

digraph dg {
    compound=true;
    labelloc="t";
    label="test.cpp";
    Vehicle;
    Make;
    subgraph clusterFord {
        label="Ford"
        Ford[shape="none"][style="invis"][label=""];
        Mustang -> Vehicle [label="private"];
        Thunderbird -> Vehicle [label="private"];
    }
    Ford -> Make [label="public"][ltail ="clusterFord"];
    subgraph clusterChevrolet {
        label="Chevrolet"
        Chevrolet[shape="none"][style="invis"][label=""];
        Camero -> Vehicle [label="private"];
    }
    Chevrolet -> Make [label="public"][ltail ="clusterChevrolet"];
}

生成此图像：

“车辆”节点应该在“福特”子图之外。我在这里想念什么？

Answer 1

这将给你想要的：

digraph dg {
    compound=true;
    labelloc="t";
    label="test.cpp";
    subgraph clusterFord {
        label="Ford"
        Ford[shape="none"][style="invis"][label=""];
        Mustang
        Thunderbird
    }
    subgraph clusterChevrolet {
        label="Chevrolet"
        Chevrolet[shape="none"][style="invis"][label=""];
        Camero
    }
    Ford -> Make [label="public"][ltail ="clusterFord"];
    Chevrolet -> Make [label="public"][ltail ="clusterChevrolet"];
    Mustang -> Vehicle [label="private"];
    Thunderbird -> Vehicle [label="private"];
    Camero -> Vehicle [label="private"];
}