>> x0 = [0.1; 1.9]
x0 =
    0.1000
    1.9000
>> [root,ok] = newton_sys(x0, 'simple_2d', 'simple_2d_prime', 1e-10, 25)
i =
     1
x =
    0.0362
    1.2124
i =
     2
x =
    0.0058
    1.0182
i =
     3
x =
    0.0001
    1.0001
i =
     4
x =
    0.0000
    1.0000
i =
     5
x =
    0.0000
    1.0000
root =
    0.0000
    1.0000
ok =
     1
>> diary off