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Chapter 7.2 - 1st Layer Normalization


Residual Output

= [
[1.133, -0.299, 0.503],
[-0.176, 0.911, 0.143],
[0.766, 0.781,-0.518],
[1.601, -0.669,0.368],
[0.663, 0.779,0.648]
]

we calculate mean row by row (showing first row eg.)

mean = (1.133 - 0.299 + 0.503) / 3 ≈ 0.446

Calculate standard daviation

1.133 - 0.446, = 0.687, -0.299 - 0.446, = -0.745, 0.503 - 0.446 = 0.057

so final top row

[ 0.687, -0.745, 0.057 ]

calculate squares

variance = average((x - mean)²) [ 0.687², (-0.745)², 0.057² ] = [ 0.472, 0.555, 0.003 ]

Calculate average

variance = (0.472 + 0.555 + 0.003)/3
variance = 0.343

Add epsilon

variance + ε ≈ 0.343

Calculate standard daviation

standard daviation = √(variance + ε ) = √0.343 ≈ 0.586

Divide by standard deviation

[ 0.687 / 0.586, -0.745 / 0.586, 0.057 / 0.586 ] =[ 1.17, -1.27, 0.10 ]

Apply gamma and beta (optional)

LayerNorm = γ × normalized + β values example : γ = [1,1,1]
β = [0,0,0]

final result top row :

LayerNorm Output
= [ 1.17, -1.27, 0.10 ]

after doing with every row we get :

LayerNorm Output = [
[ 1.40,-1.52, 0.12],
[-1.15, 1.29,-0.14],
[ 0.71, 0.70,-1.41],
[ 1.31,-1.14,-0.17],
[-0.16, 0.91,-0.75]
]