By default the DrawGraph command draws the edges and vertices of the graph with the same set of style options. The command StyleEdge, allows you to specify individual styles for specified edges overriding the default or a previously set style.

Precise control of the style can be set using stylesheet options. The stylesheet options are understood as modifiers to the default style. So, for example, if a color is not specified the default color is used.

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

$\mathrm{K5}≔\mathrm{CompleteGraph}\left(5\right)$

$\mathrm{K5}≔\mathrm{Graph\; 1:\; an\; undirected\; graph\; with\; 5\; vertices\; and\; 10\; edge(s)}$

$\mathrm{StyleEdge}\left(\mathrm{K5}\,\left\{1\,2\right\}\,\mathrm{color}=''Red''\right)$

$\mathrm{DrawGraph}\left(\mathrm{K5}\right)$

$\mathrm{StyleEdge}\left(\mathrm{K5}\,\left[\left\{2\,3\right\}\,\left\{4\,5\right\}\right]\,\mathrm{thickness}=3\right)$

$\mathrm{DrawGraph}\left(\mathrm{K5}\right)$

$\mathrm{ST}≔\mathrm{SpanningTree}\left(\mathrm{K5}\right)$

$\mathrm{ST}≔\mathrm{Graph\; 2:\; an\; undirected\; graph\; with\; 5\; vertices\; and\; 4\; edge(s)}$

$\mathrm{K5\_with\_ST}≔\mathrm{StyleEdge}\left(\mathrm{K5}\,\mathrm{ST}\,\mathrm{color}=''Gold''\,\mathrm{inplace}=\mathrm{false}\right)$

$\mathrm{K5\_with\_ST}≔\mathrm{Graph\; 3:\; an\; undirected\; graph\; with\; 5\; vertices\; and\; 10\; edge(s)}$

$\mathrm{DrawGraph}\left(\mathrm{K5\_with\_ST}\right)$

$\mathrm{DrawGraph}\left(\mathrm{K5}\right)$

$M≔\mathrm{Matrix}\left(\left[\left[0\,2\,9\right]\,\left[4\,0\,1\right]\,\left[3\,0\,0\right]\right]\right)$

$M≔\left[\begin{array}{ccc}0& 2& 9\\ 4& 0& 1\\ 3& 0& 0\end{array}\right]$

$G≔\mathrm{Graph}\left(M\right)$

$G≔\mathrm{Graph\; 4:\; a\; directed\; weighted\; graph\; with\; 3\; vertices\; and\; 5\; arc(s)}$

$\mathrm{StyleEdge}\left(G\,\left[2\,3\right]\,\mathrm{fontstyle}=''bold''\,\mathrm{fontcolor}=''Red''\,\mathrm{color}=''Green''\,\mathrm{thickness}=3\right)$

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

$P≔\mathrm{SpecialGraphs}:-\mathrm{PetersenGraph}\left(\right)$

$P≔\mathrm{Graph\; 5:\; an\; undirected\; graph\; with\; 10\; vertices\; and\; 15\; edge(s)}$

$\mathrm{P1}≔\mathrm{InducedSubgraph}\left(P\,\left[1\,2\,3\,4\,5\right]\right)$

$\mathrm{P1}≔\mathrm{Graph\; 6:\; an\; undirected\; graph\; with\; 5\; vertices\; and\; 5\; edge(s)}$

$\mathrm{P2}≔\mathrm{InducedSubgraph}\left(P\,\left[6\,7\,8\,9\,10\right]\right)$

$\mathrm{P2}≔\mathrm{Graph\; 7:\; an\; undirected\; graph\; with\; 5\; vertices\; and\; 5\; edge(s)}$

$\mathrm{StyleEdge}\left(P\,\left[\mathrm{P1}\,\mathrm{P2}\right]\,\left[\mathrm{color}=''Blue''\right]\,\left[\mathrm{color}=''Green''\right]\right)$

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

$\mathrm{StyleEdge}\left(P\,\left[\left\{1\,6\right\}\,\left\{2\,9\right\}\,\left\{3\,7\right\}\,\left\{4\,10\right\}\,\left\{5\,8\right\}\right]\,\left[\mathrm{seq}\left(\left[\mathrm{thickness}=i\right]\,i=2..10\,2\right)\right]\right)$

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

The GraphTheory[StyleEdge] command was introduced in Maple 2020.

For more information on Maple 2020 changes, see Updates in Maple 2020.