I want to visualize a network in which a part of the edges are directed,
others are not. Is this possible with igraph? It would really help me,
as igraph visualization is really great.
As I do not intend to calculate with the network, but only visualize it,
a "dirty" method would also be alright. For example I tried to look for
an option to set the size of specific arrow heads to zero, but I found
none.