Matrix multiplication

[IgorTo]

Hi,
my objective function is:

def F(x):
    A = np.diag(np.random.rand(100))
    return np.diag(x**2) @ A @ x

For x0 = np.random.rand(100), the command:
F(ad.seed(x0))
returns:
ValueError: Input must be 1- or 2-d.

Is a matrix multiplication in an objective function unsupported?