Graphviz：将边缘标签放在另一侧

Question

这可能与How to place edge labels ON edge in graphviz有关：我有以下图表，我使用命令dot -Teps g.dot > g.eps可视化：

graph triple {
    node [shape=box]; User; Object; Tag;
    node [shape=diamond,style=filled]; Triple;
    {
        User -- Triple [label = "1"];
        Object -- Triple [label = "1"];
    }
    {
        rank=same;
        User;
        Object;
    }
    Triple -- Tag [label="n"];
}

我希望通过在图表的左侧放置User和Triple之间的标签来使结果更加对称。

Answer 1

使用graphviz无法手动放置边缘标签。

但是，您可以使用headlabel，labeldistance和labelangle属性：

graph triple {
node [shape=box]; User; Object; Tag;
node [shape=diamond,style=filled]; Triple;
    {
        User   -- Triple [headlabel = "1", labeldistance=2.5, labelangle=20];
        Object -- Triple [headlabel = "1", labeldistance=2.5, labelangle=-20];
    }
    {
        rank=same;
        User;
        Object;
    }
    Triple -- Tag [label="n"];
}

输出：

Answer 2

以下是使用splines=false和双边的第二种解决方法：

graph {
splines=false;
node [shape=box]; User; Object; Tag;
node [shape=diamond,style=filled]; Triple;
    {
        User   -- Triple [label = "1"];
        User   -- Triple [label = ""];
        Object -- Triple [label = ""];
        Object -- Triple [label = "1"];
    }
    {
        rank=same;
        User;
        Object;
    }
    Triple -- Tag [label="n"];
}

输出：