ex5-biasVSvariance的练习中moduleTNC.minimize报错

[rrwang05]

您好，练习5中的多项式特征大于2的时候，执行报错
X_poly, Xval_poly, Xtest_poly = prepare_poly_data(X, Xval, Xtest, power=8)
plot_learning_curve(X_poly, y, Xval_poly, yval, l=0)

linear_regression_np(X[:i, :], y[:i], l=1)
res = opt.minimize(fun=regularized_cost, x0=theta, args=(X, y, l), method='TNC', jac=regularized_gradient,
options={'disp': True})
File "", line 1, in
rc, nf, nit, x = moduleTNC.minimize(func_and_grad, x0, low, up, scale,
ValueError: tnc: invalid return value from minimized function.

能帮忙看一下吗？