Need an adjoint for constructor VectorOfArray

[ibulu]

I have a loss function such as below:

function loss(params)
    sol_ = solve(prob_seird, Tsit5(),p=params, abstol = 1e-8, reltol = 1e-6, 
           saveat=tsteps)
    sol = convert(Array,VectorOfArray(sol_.u))
    l1 = sum((diff(sol[:,1,:],dims=2)-epi_array[:,1,2:end]).^2)
    l2 = sum((diff(sol[:,10,:],dims=2)-epi_array[:,2,2:end]).^2)
    println(size(l1))
    return l1+l2
end

where sol_.u is Array{Array{Float64,2},1} and epic_array is Array{Float32,3}. I use convert to turn sol_.u into Array{Float32,3}.
Solution is from:

function SEIRD_mobility_coupled_outer(mobility_, coupling_matrix_, nn_)
    
    function SEIRD_mobility_coupled_inner(du, u, p_, t)
        s =@view u[:,1]
        e =@view u[:,2]
        id1 =@view u[:,3]
        id2 =@view u[:,4] 
        id3 =@view u[:,5] 
        id4 =@view u[:,6] 
        id5 =@view u[:,7] 
        id6 =@view u[:,8] 
        id7 =@view u[:,9] 
        d =@view u[:,10] 
        ir1 =@view u[:,11] 
        ir2 =@view u[:,12] 
        ir3 =@view u[:,13] 
        ir4 =@view u[:,14] 
        ir5 =@view u[:,15]
        r =@view u[:,16] 
        
        ds =@view du[:,1]
        de =@view du[:,2]
        did1 =@view du[:,3]
        did2 =@view du[:,4] 
        did3 =@view du[:,5] 
        did4 =@view du[:,6] 
        did5 =@view du[:,7] 
        did6 =@view du[:,8] 
        did7 =@view du[:,9] 
        dd =@view du[:,10] 
        dir1 =@view du[:,11] 
        dir2 =@view du[:,12] 
        dir3 =@view du[:,13] 
        dir4 =@view du[:,14] 
        dir5 =@view du[:,15]
        dr =@view du[:,16]
        
        κ, α, γ = softplus.(p_[1:3])
    # κ*α and γ*η are not independent. The probablibility of transition from e to Ir and Id has to add up to 1
        η = - log(-expm1(-κ*α))/(γ+1.0e-8) 
        n_c = size(coupling_matrix_,1)
        scaler_ = softplus.(p_[4:3+n_c])
        cm_ = scaler_ .* coupling_matrix_[:,:,Int32(round(t+1.0))]
        p_nnet = p_[4+n_c:end]
        β = nn_(mobility_[:,:,Int32(round(t+1.0))], p_nnet)[1,:]
        i = id1+id2+id3+ir1+ir2+ir3+ir4+ir5
        c1 = (reshape(i,1,:)*transpose(cm_))[1,:]
        c2 = cm_*i
        a = β .* s .* i + β .* s .* (c1+c2)
        @. ds = -a
        @. de = a - κ*α*e - γ*η*e
        @. did1 = κ*(α*e-id1)
        @. did2 = κ*(id1-id2)
        @. did3 = κ*(id2-id3)
        @. did4 = κ*(id3-id4)
        @. did5 = κ*(id4-id5)
        @. did6 = κ*(id5-id6)
        @. did7 = κ*(id6-id7)
        @. dd = κ*id7
        
        @. dir1 = γ*(η*e-ir1)
        @. dir2 = γ*(ir1-ir2)
        @. dir3 = γ*(ir2-ir3)
        @. dir4 = γ*(ir3-ir4)
        @. dir5 = γ*(ir4-ir5)
        @. dr = γ*ir5
    end
end

where each component i.e. ds, de, dir1 etc has a dimension of 104. Initial conditions are constructed:

using RecursiveArrayTools
ifr = 0.007
n_counties = size(coupling_matrix,1) 
n = ones(n_counties)
ic0 = epi_array[1,:,1]
d0 = epi_array[1,:,2]
r0 = d0/ifr
s0 = n-ic0-r0-d0
e0 = ic0
id10=id20=id30=id40=id50=id60=id70=ic0*ifr/7.0
ir10=ir20=ir30=ir40=ir50=ic0*(1.0-ifr)/5.0
u0 = [s0, 
      e0,
      id10,id20,id30,id40,id50, id60, id70, d0,
      ir10,ir20,ir30,ir40,ir50,r0];
u0 = VectorOfArray([s0, 
                    e0,
                    id10,id20,id30,id40,id50, id60, id70, d0,
                    ir10,ir20,ir30,ir40,ir50, r0]);
u0 = convert(Array,u0);

When I try to calculate the gradient

Zygote.gradient(loss,p_init)

I am getting:
Need an adjoint for constructor VectorOfArray{Float64,3,Array{Array{Float64,2},1}}

[ChrisRackauckas]

sol = convert(Array,VectorOfArray(sol_.u)) that's not necessary. It already acts as an AbstractDiffEqArray <: AbstractVectorOfArray, so Array(sol) works. That should be all that's needed for your use case?

But I'll add the missing constructor anyways.

[ibulu]

Thank you. Yep. that makes sense