import numpy as np

J = np.array([
    [2, 3, 0],
    [0, 3, 0],
    [6, 0, 4]
])

xi = np.array([1, 2, 3])
xi_col = xi.reshape(-1, 1)
print(xi_col)
xi_row = xi_col.reshape(1, -1).flatten()
print(xi_row)

# Spaltenvektor-Variante
res_col = xi[:, None] - J @ xi[:, None]

# Zeilenvektor-Variante
res_row = xi[None, :] - xi[None, :] @ J

print("Spaltenvektor:")
print(res_col[0,0])
print("Zeilenvektor:")
print(res_row)