ERROR: LoadError: Need an adjoint for constructor SparseMatrixCSC{Float64,Int64}. Gradient is of type Array{Float64,2}. #742
Description
In the following case,
using SparseArrays,Zygote
function loss_rd(x::AbstractArray{T,1}) where{T}
f = ones(T, 3)
K = sparse(I, J, x)
u = K \ f
return sum(abs2, u)
end
# case that does not work
I = [1, 1, 2, 3, 3]
J = [1, 3, 2, 3, 1]
x = [3.0, 1.0, 3.0, 3.0, 1.0]
println("loss_rd=", loss_rd(x))
dldx=Zygote.gradient(loss_rd,x)
println("Zygnote, dl/dx=",dldx)
I got the error,
ERROR: Need an adjoint for constructor SparseMatrixCSC{Float64,Int64}. Gradient is of type Array{Float64,2}
Stacktrace:
[1] error(::String) at ./error.jl:33
[2] (::Zygote.Jnew{SparseMatrixCSC{Float64,Int64},Nothing,false})(::Array{Float64,2}) at /Users/6pz/.julia/packages/Zygote/1GXzF/src/lib/lib.jl:306
[3] (::Zygote.var"#380#back#194"{Zygote.Jnew{SparseMatrixCSC{Float64,Int64},Nothing,false}})(::Array{Float64,2}) at /Users/6pz/.julia/packages/ZygoteRules/6nssF/src/adjoint.jl:49
[4] SparseMatrixCSC at /Users/julia/buildbot/worker/package_macos64/build/usr/share/julia/stdlib/v1.4/SparseArrays/src/sparsematrix.jl:32 [inlined]
[5] (::typeof(∂(SparseMatrixCSC{Float64,Int64})))(::Array{Float64,2}) at /Users/6pz/.julia/packages/Zygote/1GXzF/src/compiler/interface2.jl:0
[6] SparseMatrixCSC at /Users/julia/buildbot/worker/package_macos64/build/usr/share/julia/stdlib/v1.4/SparseArrays/src/sparsematrix.jl:45 [inlined]
[7] (::typeof(∂(SparseMatrixCSC)))(::Array{Float64,2}) at /Users/6pz/.julia/packages/Zygote/1GXzF/src/compiler/interface2.jl:0
[8] sparse! at /Users/julia/buildbot/worker/package_macos64/build/usr/share/julia/stdlib/v1.4/SparseArrays/src/sparsematrix.jl:824 [inlined]
[9] (::typeof(∂(sparse!)))(::Array{Float64,2}) at /Users/6pz/.julia/packages/Zygote/1GXzF/src/compiler/interface2.jl:0
[10] sparse at /Users/julia/buildbot/worker/package_macos64/build/usr/share/julia/stdlib/v1.4/SparseArrays/src/sparsematrix.jl:661 [inlined]
[11] (::typeof(∂(sparse)))(::Array{Float64,2}) at /Users/6pz/.julia/packages/Zygote/1GXzF/src/compiler/interface2.jl:0
[12] sparse at /Users/julia/buildbot/worker/package_macos64/build/usr/share/julia/stdlib/v1.4/SparseArrays/src/sparsematrix.jl:850 [inlined]
[13] (::typeof(∂(sparse)))(::Array{Float64,2}) at /Users/6pz/.julia/packages/Zygote/1GXzF/src/compiler/interface2.jl:0
[14] sparse at /Users/julia/buildbot/worker/package_macos64/build/usr/share/julia/stdlib/v1.4/SparseArrays/src/sparsematrix.jl:846 [inlined]
[15] (::typeof(∂(sparse)))(::Array{Float64,2}) at /Users/6pz/.julia/packages/Zygote/1GXzF/src/compiler/interface2.jl:0
[16] loss_rd at ./REPL[10]:3 [inlined]
[17] (::typeof(∂(loss_rd)))(::Float64) at /Users/6pz/.julia/packages/Zygote/1GXzF/src/compiler/interface2.jl:0
[18] (::Zygote.var"#37#38"{typeof(∂(loss_rd))})(::Float64) at /Users/6pz/.julia/packages/Zygote/1GXzF/src/compiler/interface.jl:45
[19] gradient(::Function, ::Array{Float64,1}) at /Users/6pz/.julia/packages/Zygote/1GXzF/src/compiler/interface.jl:54
[20] top-level scope at REPL[15]:1