graphs: how to apply functions for GRAPH to DIGRAPH
Subject: graphs: how to apply functions for GRAPH to DIGRAPH
From: Andrej Vodopivec
Date: Sat, 8 May 2010 08:25:48 +0200
On Sat, May 8, 2010 at 7:59 AM, Rolf Fankhauser
<rolf.fankhauser at gepdata.ch> wrote:
> I defined a directed graph, exported and imported it in format DIMACS. That
> works fine.
> But if I want to check if the graph is planar with function is_planar, I get
> the error "Argument 1 to 'IS_PLANAR' is not a graph: Structure [DIGRAPH].
> Why is function is_planar not applicable to DIGRAPHs ? How can I convert my
> directed graph to an undirected graph?
The function underlying_graph converts directed graphs to undirected.
HTH, Andrej