X = np.array([
    np.array([1,2,3]),
    np.array([1,2,3]),
    np.array([1,2,3]),
])
y = np.array([1, 2, 3])
theta = np.array([1, 2, 3])

print(logistic_func(theta, X[0]))
print(logistic_func_all(theta, X))
print(cross_entropy_loss(theta, X, y))
print(grad_cross_entropy_loss(theta, X, y))