Why does the NetworkX graph not draw in Cygwin?

Question

I am running Python and NetworkX (a graphing library) on Cygwin (Windows 7).

The following code creates a graph and attempts to draw it - but nothing appears on screen:

plt.ion()
nx.draw(nx.petersen_graph())
plt.show()

There don't appear to be any errors.

I have also tried saving a graph to an image using:

plt.savefig("test.png")

which creates the correct image.

Does this have to do with matplotlib and Cygwin?

Answer 1

I fixed this problem by:

1. Starting X using startxwin and running the script from there.
2. Changing the backend = agg setting to backend = tkagg in my matplotlibrc file.

Thanks to tcaswell and EdChum for the help.