如何管理graphviz中节点之间的距离？

Question

我正在尝试绘制一个包含3个节点级别的图表，这些级别之间的距离相等。 然而，graphviz以某种方式决定中间水平和底部水平之间的距离应远大于顶部和中间水平之间的距离。有什么方法可以解决这个问题吗？

这是我的代码：

digraph g{
    rankdir="LR";
    graph [pad="0.5", ranksep="0.525", nodesep="3"];
    splines=false;
    node[shape = square];
    edge[style=invis];
    subgraph cluster_3 {
        color=invis;
        a1->a2->a3->a4->a5->a6->a7;
    }
    subgraph cluster_2 {
        color=invis;
        a->b->c->d->e->f->g;
    }
    subgraph cluster_1 {
        color=invis;
        1->2->3->4->5->6->7;
    }
    "a1" [label="1'"];
    "a2" [label="2'"];
    "a3" [label="3'"];
    "a4" [label="4'"];
    "a5" [label="5'"];
    "a6" [label="6'"];
    "a7" [label="7'"];
    edge[style=solid, constraint=false];
    a->1[arrowhead=none, arrowtail=none];
    a->2[arrowhead=none, arrowtail=none];
    a->3[arrowhead=none, arrowtail=none];
    a->a1[arrowhead=none, arrowtail=none];
    a->a2[arrowhead=none, arrowtail=none];
    a->a3[arrowhead=none, arrowtail=none];
    b->1[arrowhead=none, arrowtail=none];
    b->3[arrowhead=none, arrowtail=none];
    b->7[arrowhead=none, arrowtail=none];
    b->a1[arrowhead=none, arrowtail=none];
    b->a3[arrowhead=none, arrowtail=none];
    b->a7[arrowhead=none, arrowtail=none];
    c->2[arrowhead=none, arrowtail=none];
    c->6[arrowhead=none, arrowtail=none];
    c->7[arrowhead=none, arrowtail=none];
    c->a2[arrowhead=none, arrowtail=none];
    c->a6[arrowhead=none, arrowtail=none];
    c->a7[arrowhead=none, arrowtail=none];
    d->1[arrowhead=none, arrowtail=none];
    d->4[arrowhead=none, arrowtail=none];
    d->7[arrowhead=none, arrowtail=none];
    d->a1[arrowhead=none, arrowtail=none];
    d->a4[arrowhead=none, arrowtail=none];
    d->a7[arrowhead=none, arrowtail=none];
    e->1[arrowhead=none, arrowtail=none];
    e->2[arrowhead=none, arrowtail=none];
    e->3[arrowhead=none, arrowtail=none];
    e->a1[arrowhead=none, arrowtail=none];
    e->a2[arrowhead=none, arrowtail=none];
    e->a3[arrowhead=none, arrowtail=none];
    f->1[arrowhead=none, arrowtail=none];
    f->4[arrowhead=none, arrowtail=none];
    f->7[arrowhead=none, arrowtail=none];
    f->a1[arrowhead=none, arrowtail=none];
    f->a4[arrowhead=none, arrowtail=none];
    f->a7[arrowhead=none, arrowtail=none];
    g->5[arrowhead=none, arrowtail=none];
    g->6[arrowhead=none, arrowtail=none];
    g->7[arrowhead=none, arrowtail=none];
    g->a5[arrowhead=none, arrowtail=none];
    g->a6[arrowhead=none, arrowtail=none];
    g->a7[arrowhead=none, arrowtail=none];
}

目前的输出如下：

Answer 1

只是玩了一下并想出下面的图表，这是否更接近想要？

digraph g{
    graph [pad="0.5", nodesep="1", ranksep="2"];
    splines="false";
    node[shape = square];
    edge[style=invis];
    a1->a->1
    a2->b->2
    a3->c->3
    a4->d->4
    a5->e->5
    a6->f->6
    a7->g->7

    "a1" [label="1'"];
    "a2" [label="2'"];
    "a3" [label="3'"];
    "a4" [label="4'"];
    "a5" [label="5'"];
    "a6" [label="6'"];
    "a7" [label="7'"];
    edge[style=solid, constraint=false];
    a->1[arrowhead=none, arrowtail=none];
    a->2[arrowhead=none, arrowtail=none];
    a->3[arrowhead=none, arrowtail=none];
    a->a1[arrowhead=none, arrowtail=none];
    a->a2[arrowhead=none, arrowtail=none];
    a->a3[arrowhead=none, arrowtail=none];
    b->1[arrowhead=none, arrowtail=none];
    b->3[arrowhead=none, arrowtail=none];
    b->7[arrowhead=none, arrowtail=none];
    b->a1[arrowhead=none, arrowtail=none];
    b->a3[arrowhead=none, arrowtail=none];
    b->a7[arrowhead=none, arrowtail=none];
    c->2[arrowhead=none, arrowtail=none];
    c->6[arrowhead=none, arrowtail=none];
    c->7[arrowhead=none, arrowtail=none];
    c->a2[arrowhead=none, arrowtail=none];
    c->a6[arrowhead=none, arrowtail=none];
    c->a7[arrowhead=none, arrowtail=none];
    d->1[arrowhead=none, arrowtail=none];
    d->4[arrowhead=none, arrowtail=none];
    d->7[arrowhead=none, arrowtail=none];
    d->a1[arrowhead=none, arrowtail=none];
    d->a4[arrowhead=none, arrowtail=none];
    d->a7[arrowhead=none, arrowtail=none];
    e->1[arrowhead=none, arrowtail=none];
    e->2[arrowhead=none, arrowtail=none];
    e->3[arrowhead=none, arrowtail=none];
    e->a1[arrowhead=none, arrowtail=none];
    e->a2[arrowhead=none, arrowtail=none];
    e->a3[arrowhead=none, arrowtail=none];
    f->1[arrowhead=none, arrowtail=none];
    f->4[arrowhead=none, arrowtail=none];
    f->7[arrowhead=none, arrowtail=none];
    f->a1[arrowhead=none, arrowtail=none];
    f->a4[arrowhead=none, arrowtail=none];
    f->a7[arrowhead=none, arrowtail=none];
    g->5[arrowhead=none, arrowtail=none];
    g->6[arrowhead=none, arrowtail=none];
    g->7[arrowhead=none, arrowtail=none];
    g->a5[arrowhead=none, arrowtail=none];
    g->a6[arrowhead=none, arrowtail=none];
    g->a7[arrowhead=none, arrowtail=none];
}

Answer 2

要添加到@uncletall答案（并部分解决@ ingomueller.net问题），看来nodeep和ranksep在如何分离节点方面有很大的影响：

http://www.graphviz.org/doc/info/attrs.html#d:nodesep

nodesep：双精度，默认值：0.25，最小值：0.02 指定同一节点中两个相邻节点之间的最小间距 排名，以英寸为单位。

对于其他布局，nodesep会影响节点上循环之间的间距 单节点或一对节点之间的多边。

对以下图形有效：

http://martin-loetzsch.de/S-DOT/ranksep.html

给出所需的等级间隔，以英寸为单位。这是最低的 一排节点的底部与节点之间的垂直距离 节点的顶部。