def covarianceMatrix(A, B):
    """ Returns the covariance matrix of two given matrices `A` and `B`.
    Args
    ---
    `A : np.array` A `m` x `n` numpy matrix
    `B : np.array` A `m` x `n` numpy matrix
    
    Returns
    ---
    `cMatrix : np.array` The covariance matrix
    """
    N = len(A[0])
    C = (A @ B.T) / N
    return C