[igraph] How to read in a large graph (and output a sparse matrix)

[Raphael C]

I have 8GB of RAM and I have a simple edge list text file of size
1.2GB. It was 62500000 edges and about half that many vertices. Each
line looks like

     287111206 357850135

I would like to read in the graph and output a sparse adjacency
matrix. I am failing on all counts.  I have tried


g = Graph.Read_Edgelist('edges.txt')

but this fails immediately with

MemoryError: Error at vector.pmt:439: cannot reserve space for vector,
Out of memory

This seems unrelated to the size of the graph is just a function of
the node ids being large.

So instead I tried

g = Graph.Read_Ncol('edges.txt')

This eats up all the RAM in my PC forcing me to kill the code.

I fact I tested g = Graph.Read_Ncol('edges.txt') with the first 1/5 of
the edges and have the same memory problem.

Each node id is a 32 bit integer so the graph should fit easily in 8GB of RAM.

What can I do?

Thanks very much for any help.
Raphael