Is there a difference or is it just terminology?

  • 1
    $\begingroup$ Just figured that the authors are French. In french an undirected graph is called "un graphe non orienté". This is a strong - but I'm still unsure. $\endgroup$ – Lonforce Mar 1 '13 at 14:31
  • 2
    $\begingroup$ mathworld.wolfram.com/OrientedGraph.html explains a difference in use between the two terminologies. I'm not convinced that this is standard, but perhaps a graph theorist can weigh in on the issue. $\endgroup$ – Lee Mosher Mar 1 '13 at 15:54
  • $\begingroup$ @Lonforce: strictly speaking a negative by itself does not define much, or anything. This is a basic tenet of constructive mathematics. Surprising that you seem to have thought this question defined. $\endgroup$ – Peter Heinig Aug 8 '17 at 15:37

Many people consider that an "oriented graph" is what you get from a simple undirected graph when you assign a direction to each edge. The difference between that and "directed graph" is that a directed graph can have cycles of length 2 even if it is qualified as "simple", whereas an "oriented graph" cannot. On the other hand, there are zillions of papers that use "oriented graph" with identical meaning to "directed graph".

Applying these meanings pedantically in the negative doesn't seem to be a good idea. I'd be very surprised to see anyone using "non-oriented" of a digraph to imply that it doesn't have 2-cycles. I only recall "non-oriented" meaning that the edges don't have directions, which is the same as "undirected".

| cite | improve this answer | |

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.