Plot undeformed configuration

[dokken]

This seems like a matplotlib issue, not a DOLFIN issue,as here is the same field shown in Paraview, using:

with fe.XDMFFile("test.xdmf") as xdmf:
    xdmf.write(u)

while

plt.figure()
fe.plot(u)  # , mode="displacement")
plt.savefig("disp.png")

yields