pick beta from state in NADAM

src/optimise/optimisers.jl

@@ -214,7 +214,7 @@ NADAM(η = 0.001, β = (0.9, 0.999)) = NADAM(η, β, IdDict())
 function apply!(o::NADAM, x, Δ)
   η, β = o.eta, o.beta
   β1p, β2p = o.beta
-  mt, vt = get!(o.state, x, (zero(x), zero(x)))
+  mt, vt, (β1p, β2p) = get!(o.state, x, (zero(x), zero(x), o.beta))
   @. mt = β[1] * mt + (1 - β[1]) * Δ
   @. vt = β[2] * vt + (1 - β[2]) * Δ^2
   @. Δ = (β[1] * mt / (1 - β[1] * β1p) + (1 - β[1]) * Δ / (1 - β1p)) / (√(vt * β[2] / (1 - β2p)) + ϵ) * η