Right to left edges in dot (Graphviz)

Question

I'm trying to display edges going from right to left (i.e. backwards) using dot:

A <= B => C

The best I could do was:

digraph {
  a->b;
  c->a [dir="back"];
  {rank=same;a b c}
}

..which is fine, except I don't like using "c->a" when the edge is directed the other way.

So I wanted to share this solution (which didn't seem to be mentioned on SO) and check if I'm missing something obvious.

See: http://www.graphviz.org/doc/info/attrs.html#k%3AdirType

Answer 1

I have no alternative to your usage of dir, but i can make it slightly shorter, if you want horizontal alignment, use the rankdir property of graph, to force direction from left to right.

    digraph {
      [rankdir=LR];
      a->b;
      c->a [dir="back"];
    }