~~ Methods for function mk_even_graph. Each of these return an instance of even_graph, where all nodes are of even degree. The result satisfies is_even_graph.
The resulting graph yields an euler tour.
This is the workhorse method. If self does not satisfy is_even_graph, the graph is forced to be even by one of the folowing. If add_edges is TRUE, the odd nodes are paired off and a new edge added between each pair, possibly duplicating an existing edge. If add_edges is a vector of the odd nodes, they are paired off in this order.
If add_edges is FALSE a new dummy node is added with
edges going to all odd nodes.
first constructs a complete graph using mk_complete_graph, which is then augmented to be even.
first constructs a complete graph using mk_complete_graph, which is then augmented to be even.
first constructs a complete graph using mk_complete_graph, which is then augmented to be even.
returns self.
see overview