Use this if you are using igraph from R
graph_from_graphnel {igraph}  R Documentation 
The graphNEL class is defined in the graph
package, it is another
way to represent graphs. graph_from_graphnel
takes a graphNEL
graph and converts it to an igraph graph. It handles all
graph/vertex/edge attributes. If the graphNEL graph has a vertex
attribute called ‘name
’ it will be used as igraph vertex
attribute ‘name
’ and the graphNEL vertex names will be
ignored.
graph_from_graphnel(graphNEL, name = TRUE, weight = TRUE, unlist.attrs = TRUE)
graphNEL 
The graphNEL graph. 
name 
Logical scalar, whether to add graphNEL vertex names as an
igraph vertex attribute called ‘ 
weight 
Logical scalar, whether to add graphNEL edge weights as an
igraph edge attribute called ‘ 
unlist.attrs 
Logical scalar. graphNEL attribute query functions
return the values of the attributes in R lists, if this argument is

Because graphNEL graphs poorly support multiple edges, the edge attributes of the multiple edges are lost: they are all replaced by the attributes of the first of the multiple edges.
graph_from_graphnel
returns an igraph graph object.
as_graphnel
for the other direction,
as_adj
, graph_from_adjacency_matrix
,
as_adj_list
and graph.adjlist
for other
graph representations.
## Not run:
## Undirected
g < make_ring(10)
V(g)$name < letters[1:10]
GNEL < as_graphnel(g)
g2 < graph_from_graphnel(GNEL)
g2
## Directed
g3 < make_star(10, mode="in")
V(g3)$name < letters[1:10]
GNEL2 < as_graphnel(g3)
g4 < graph_from_graphnel(GNEL2)
g4
## End(Not run)