Important: The networks package has been deprecated.  Use the superseding command GraphTheory[AddEdge] instead.

Add one or more edges to a graph by creating new edges for the specified sets or lists of vertices. An expression sequence of the names used for the new edges is returned.

An undirected edge is indicated by a set of vertices.

A directed edge is represented by a list of two vertices.  The tail is the first vertex and the head is the second vertex.

To force addedge() to use a specific name for a new edge use an optional argument names=edg1.  All edge names must be names or strings that begin with the letter `e`.

To force addedge() to use a specific weight use an optional argument (eg. weights=3).

If more than one edge is to be added the connections must be presented as a list or set of pairs of vertices.  In the case of lists of pairs of vertices, specific names and weights can still be provided by specifying names=L1 and weights=L2 where L1 and L2 are appropriate lists. To name or provide optional weights for more than one edge or vertex at a time then use lists for each of the required items.

This routine is normally loaded via the command with(networks) but may also be referenced using the full name networks[addedge](...).

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

$\mathrm{new}\left(G\right)\:$

$\mathrm{addvertex}\left(\left\{1\,2\,3\,4\right\}\,G\right)\:$

$\mathrm{addedge}\left(\mathrm{Cycle}\left(1\,2\,3\,4\right)\,G\right)\:$

$\mathrm{edg}≔\mathrm{addedge}\left(\left[1\,2\right]\,G\right)$

$\mathrm{edg}≔\mathrm{e5}$

$\mathrm{head}\left(\mathrm{edg}\,G\right)$

$2$

$\mathrm{tail}\left(\mathrm{edg}\,G\right)$

$1$

$\mathrm{addedge}\left(\left[1\,2\right]\,\mathrm{names}=\mathrm{edg1}\,G\right)$

$\mathrm{edg1}$

$\mathrm{addedge}\left(\left[\left\{1\,2\right\}\,\left\{2\,3\right\}\right]\,\mathrm{names}=\left[\mathrm{edg2}\,''edg3''\right]\,\mathrm{weights}=\left[0\,0\right]\,G\right)$

$\mathrm{edg2},''edg3''$

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

$\left\{''edg3''\,\mathrm{e1}\,\mathrm{e2}\,\mathrm{e3}\,\mathrm{e4}\,\mathrm{e5}\,\mathrm{edg1}\,\mathrm{edg2}\right\}$