GraphViz: How to change arrowhead type?

Question

I want to simulate non-directional graphs with .dot. To that end, I want the arrowhead type to be "none". How do I set this?

"f" -> "t" [label=2],[arrowhead=none]
"m" -> "d" [label=0],[arrowhead=none]

The above is not working.

Answer 1

Use headport instead of arrowhead. More info here.

Answer 2

"f" -> "t" [label=2 arrowhead=none] "m" -> "d" [label=0 arrowhead=none]

Answer 3

Another nice way is to use the 'dir' attribute:

   "f" -> "t" [label=2 dir=none]
   "m" -> "d" [label=0 dir=none]

See also http://martin-loetzsch.de/DOTML/dir.html

Answer 4

Replace 'digraph {' on the top line of your dot file with 'graph {'. Then, change your node relationships to: a -- b;