This is the official demo(https://nbviewer.ipython.org/github/qutip/qutip-notebooks/blob/master/examples/visualization-exposition.ipynb). But after I run it, there is no error, but I can't output the graph of the Bloch sphere. This does not match the case. In addition, use display(b.b.make_sphere()) to return None. Something magical happened, what a beautiful day.
%matplotlib inline import pandas as pd import matplotlib.pyplot as plt import numpy as np from qutip import * H = sigmaz() + 0.3 * sigmay() e_ops = [sigmax(), sigmay(), sigmaz()] times = np.linspace(0, 10, 100) psi0 = (basis(2, 0) + basis(2, 1)).unit() result = mesolve(H, psi0, times, , e_ops) plot_expectation_values(result) b = Bloch() b.add_vectors(expect(H.unit(), e_ops)) b.add_points(result.expect, meth='l') b.make_sphere()