x = np.linspace(0, 2.*np.pi, 101)
y = x
X, Y = np.meshgrid(x, y)
z = np.sin(X) * np.sin(Y)

entry = NXentry()
entry.data = NXdata(z, (y, x))
print(entry.tree)
entry.plot()
nxtree.example = NXroot(entry)