How do I place nodes on the same level in DOT?
Solution 1:
Putting the rank = same; ...
statements in braces, e.g.:
digraph G {
rankdir = TB;
subgraph {
A -> B
A -> C
C -> D
X -> Y
// note that rank is used in the subgraph
{rank = same; A; X;}
{rank = same; B; D; Y;}
} /* closing subgraph */
}
... gives the desired result:
Solution 2:
The ideal structure is actually rank max and rank min. No need for a subgraph or any other shenanigans. GraphViz has explicit facilities for this.
With complex graphs, rank=same will often end up near the middle of the graph. If you mean top and bottom, say top and bottom.
digraph G {
rankdir = TB;
A -> B;
A -> C -> D;
X -> Y;
{ rank=min; A; X; }
{ rank=max; B; D; Y; }
}
Solution 3:
Here's a simple example inspired by @William John Holden's comment -
graph {
rankdir=LR;
a -- b -- c;
d -- e -- f;
b -- d; {rank = same; b; d;};
}