Skip to content
New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Tweak getindex implementation + test corner cases #547

Merged
merged 4 commits into from
Apr 14, 2020
Merged

Tweak getindex implementation + test corner cases #547

Show file tree
Hide file tree
Changes from all commits
Commits
Show all changes
4 commits
Select commit Hold shift + click to select a range
b3d0ef7
Tweak getindex implementation + test corner cases
willtebbutt Mar 18, 2020
c1caed8
Oops
willtebbutt Mar 18, 2020
d81625b
Tweaks
willtebbutt Mar 18, 2020
ac52149
Resolves merge conflict
willtebbutt Apr 9, 2020
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
13 changes: 7 additions & 6 deletions src/lib/array.jl
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -30,25 +30,26 @@ end
@adjoint (::Type{T})(sz) where {T<:Zeros} = T(sz), Δ->(nothing,)
@adjoint (::Type{T})(sz) where {T<:Ones} = T(sz), Δ->(nothing,)

_zero(xs::AbstractArray{<:Number}, T=float(eltype(xs))) = fill!(similar(xs, T), false)
_zero(xs::AbstractArray, T=Any) = Union{Nothing, T}[nothing for x in xs]

@adjoint getindex(x::AbstractArray, inds...) = x[inds...], ∇getindex(x, inds)

@adjoint view(x::AbstractArray, inds...) = view(x, inds...), ∇getindex(x, inds)

∇getindex(x::AbstractArray, inds) = dy -> begin
if inds isa NTuple{<:Any,Integer}
if inds isa NTuple{<:Any, Integer}
dx = _zero(x, typeof(dy))
dx[inds...] = dy
else
dx = _zero(x, eltype(dy))
dxv = view(dx, inds...)
dxv .+= _droplike(dy, dxv)
dxv .= accum.(dxv, _droplike(dy, dxv))
end
(dx, map(_->nothing, inds)...)
return (dx, map(_->nothing, inds)...)
end

_zero(xs::AbstractArray{<:Number}, T::Type{Nothing}) = fill!(similar(xs), zero(eltype(xs)))
_zero(xs::AbstractArray{<:Number}, T) = fill!(similar(xs, T), false)
_zero(xs::AbstractArray, T) = fill!(similar(xs, Union{Nothing, T}), nothing)

_droplike(dy, dxv) = dy
_droplike(dy::Union{LinearAlgebra.Adjoint, LinearAlgebra.Transpose}, dxv::AbstractVector) =
dropdims(dy; dims=2)
Expand Down
34 changes: 21 additions & 13 deletions test/gradcheck.jl
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -138,33 +138,41 @@ end
@test gradient(logdet, 2.0)[1] == 0.5

@testset "getindex" begin
@test gradtest(x -> x[:,2,:], (3,4,5))
@test gradtest(x -> x[1:2,3:4], (3,4))
@test gradtest(x -> x[:, 2, :], (3, 4, 5))
@test gradtest(x -> x[1:2, 3:4], (3, 4))

imat = [1 2; 3 4]
@test gradtest(x -> x[:,imat], (3,4))
@test gradtest(x -> x[:,[1,2,2]], (3,4))
@test gradtest(x -> x[:, imat], (3, 4))
@test gradtest(x -> x[:, [1, 2, 2]], (3, 4))
irep = [1 2; 2 2]
@test gradtest(x -> x[1,irep], (3,4))
@test gradtest(x -> x[1, irep], (3, 4))

# https://github.com/invenia/Nabla.jl/issues/139
x = rand(3)
z = [1,2,3,3]
y(x,z) = dot(ones(4), x[z])
@test gradient(y, x,z) == ([1,1,2], nothing)
z = [1, 2, 3, 3]
y(x, z) = dot(ones(4), x[z])
@test gradient(y, x, z) == ([1, 1, 2], nothing)

# https://github.com/FluxML/Zygote.jl/issues/376
_, back = Zygote._pullback(x->x[1]*im, randn(2))
@test back(1.0)[2] == [-im, 0]

# _droplike
@test gradient(x -> sum(inv, x[1,:]'), ones(2,2)) == ([-1 -1; 0 0],)
@test gradient(x -> sum(inv, x[1:1,:]'), ones(2,2)) == ([-1 -1; 0 0],)
@test gradient(x -> sum(inv, transpose(view(x,1,:))), ones(2,2)) == ([-1 -1; 0 0],)
@test gradient(x -> sum(inv, x[1, :]'), ones(2, 2)) == ([-1 -1; 0 0],)
@test gradient(x -> sum(inv, x[1:1, :]'), ones(2, 2)) == ([-1 -1; 0 0],)
@test gradient(x -> sum(inv, transpose(view(x, 1, :))), ones(2, 2)) == ([-1 -1; 0 0],)

# https://github.com/FluxML/Zygote.jl/issues/513
@test gradient(p -> sum(Float32[1,0] - p), [2,3]) == ([-1,-1],)
@test gradient(x -> sum(Float32[1,x] .+ x), 4) == (3.0f0,)
@test gradient(p -> sum(Float32[1, 0] - p), [2, 3]) == ([-1, -1],)
@test gradient(x -> sum(Float32[1, x] .+ x), 4) == (3.0f0,)

# Ensure that nothings work with numeric types.
_, back = Zygote.pullback(getindex, randn(4), [1])
@test back([nothing]) == (zeros(4), nothing)

# Ensure that nothings work with non-numeric types.
_, back = Zygote.pullback(getindex, [randn(2) for _ in 1:3], [1])
@test back([nothing]) == ([nothing for _ in 1:3], nothing)
end

@testset "view" begin
Expand Down