Networkx: How to create the incidence matrix from a huge graph

Question

I am reading a very big graph specifically the wiki-topcats (http://snap.stanford.edu/data/wiki-topcats.html) and while I can read and create in acceptable time the graph with:

graph = nx.read_edgelist("C:/.../wiki-topcats.txt", nodetype=int)

Then I need to extract the incidence matrix in order to create the linegraph (that's my goal) , but when I run:

C = nx.incidence_matrix(graph)

I am getting memory errors, and I cannot find any efficient way of dealing with this or maybe a way to work around this by creating the incidence matrix from the adjancency, but I must work with scipy matrices due to magnitude of the graph e.g. this adjacency matrix works.

A = nx.to_scipy_sparse_matrix(graph)

. Any help would be greatly appreciated.