The MoralGraph( G ) command constructs the moral graph of the directed graph G.

The moral graph is a graph with the same vertices as G but with all directed edges made undirected and with the property that all pairs in G which share a child are connected.

$\mathrm{with}\left(\mathrm{GraphTheory}\right)\:$

$G≔\mathrm{Graph}\left(7\,\left\{\left[1\,3\right]\,\left[2\,3\right]\,\left[2\,4\right]\,\left[3\,5\right]\,\left[3\,6\right]\,\left[3\,7\right]\,\left[4\,7\right]\right\}\right)$

$G≔\mathrm{Graph\; 1:\; a\; directed\; graph\; with\; 7\; vertices\; and\; 7\; arc(s)}$

$\mathrm{NumberOfEdges}\left(G\right)$

$7$

$\mathrm{DrawGraph}\left(G\right)$

$M≔\mathrm{MoralGraph}\left(G\right)$

$M≔\mathrm{Graph\; 2:\; an\; undirected\; graph\; with\; 7\; vertices\; and\; 9\; edge(s)}$

$\mathrm{NumberOfEdges}\left(M\right)$

$9$

$\mathrm{DrawGraph}\left(M\right)$

The GraphTheory[MoralGraph] command was introduced in Maple 2024.

For more information on Maple 2024 changes, see Updates in Maple 2024.