Static Neural Network Parameters

We can also allocate neural network parameters using StaticArrays. Therefore we simply need to pass the CPUStatic() backend to the NeuralNetwork constructor.

using AbstractNeuralNetworks
import Random
Random.seed!(123)

backend = AbstractNeuralNetworks.CPUStatic()
input_dim = 2
n_hidden_layers = 100
c = Chain(Dense(input_dim, 10, tanh), Tuple(Dense(10, 10, tanh) for _ in 1:n_hidden_layers)..., Dense(10, 1, tanh))
nn = NeuralNetwork(c, backend)
typeof(params(nn).L1.W)

MMatrix{10, 2, Float64, 20} (alias for StaticArraysCore.MArray{Tuple{10, 2}, Float64, 2, 20})

We can compare different evaluation times:

nn_cpu = changebackend(CPU(), nn)
second_dim = 200
x = rand(input_dim, second_dim)
@time nn(x);

  0.002713 seconds (714 allocations: 3.109 MiB)

@time nn_cpu(x);

  0.002139 seconds (714 allocations: 3.109 MiB)

If we also make the input static, we get:

using StaticArrays
x = @SMatrix rand(input_dim, second_dim)
nn(x);
@time nn(x);

  0.002517 seconds (206 allocations: 1.555 MiB)

@time nn_cpu(x);

  0.002195 seconds (714 allocations: 3.109 MiB)