14.5.4 Undirecting Graphs

The following methods create the undirected version of a graph instance:

• Java
• Python

PgxGraph undirect()
PgxGraph undirect(String newGraphName)
PgxGraph undirect(MultiEdges multiEdges, SelfEdges selfEdges, TrivialVertices trivialVertices, Mode mode, String newGraphName)
PgxGraph undirect(Collection<VertexProperty<?, ?>> vertexProps, Collection<EdgeProperty<?>> edgeProps, MultiEdges multiEdges, SelfEdges selfEdges, Mode mode, String newGraphName)

undirect(self, vertex_properties=True, edge_properties=True, keep_multi_edges=True, keep_self_edges=True,
                 keep_trivial_vertices=True, in_place=False, name=None)

The first two methods create an undirected version of the graph while copying all of the vertex properties. newGraphName is an optional argument to specify the name of the newly created graph instance.

In contrast, the third and fourth methods concurrently perform undirecting and simplifying of a graph. See Simplifying and Copying Graphs for the meaning of each parameter.

All methods return an object of the undirected PgxGraph type.

An undirected graph has some restrictions. Some algorithms are only supported on directed graphs or are not yet supported for undirected graphs. Further, PGX does not support to store undirected graphs nor reading from undirected formats. Since the edges do not have a direction anymore, the behavior of pgxEdge.getSource() or pgxEdge.getDestination() can be ambiguous. In order to provide deterministic results, PGX will always return the vertex with the smaller internal id as source and the other as destination vertex.