Simple Neural Network in 22 lines J lang without library

X =: 4 3 $ 0 0 1 0 1 1 1 0 1 1 1 1

Y =: 4 1 $ 0 0 1 1

w =: 3 1 $ 0.5069797399 0.5703818579 0.9265880619

e =: 2.718281828459045

iter =: ^:

dot =: +/ . *

T =: |:

output =: verb define

1 % 1 + e ^ 0 - X dot y

)

train =: verb define

l1 =: output y

l1_err =: Y - l1

l1_delta =: l1_err * l1 * 1 - l1

y + (T X) dot l1_delta

)

w =: (train iter 1000) w

l1 =: output w

l1