import matplotlib.pyplot as pl
import bluebell as bb
import bluebell.plot as bbplot

mu = np.random.rand(2)
A = np.random.rand(2,2)
C = A.T.dot(A)
x = bb.vertices(mu, C)
pl.plot(*x.T, 'o')
bbplot.cov_ellipse(mu, C, fc='none', ec='k')