Skip to content

check for iszero(partials(x)) in pow #592

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

Merged
andreasnoack merged 1 commit into from
Aug 8, 2022
Merged

check for iszero(partials(x)) in pow #592

Show file tree
Hide file tree
Changes from all commits
Commits
Show all changes
1 commit
Select commit
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
2 changes: 1 addition & 1 deletion src/dual.jl
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -534,7 +534,7 @@ for f in (:(Base.:^), :(NaNMath.pow))
begin
v = value(x)
expv = ($f)(v, y)
if y == zero(y)
if y == zero(y) || iszero(partials(x))
new_partials = zero(partials(x))
else
new_partials = partials(x) * y * ($f)(v, y - 1)
Expand Down
6 changes: 6 additions & 0 deletions test/DualTest.jl
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -12,6 +12,7 @@ using DiffRules
import Calculus

struct TestTag end
struct OuterTestTag end

samerng() = MersenneTwister(1)

Expand All @@ -26,6 +27,8 @@ dual_isapprox(a::Dual{T,T1,T2}, b::Dual{T3,T4,T5}) where {T,T1,T2,T3,T4,T5} = er

ForwardDiff.:≺(::Type{TestTag()}, ::Int) = true
ForwardDiff.:≺(::Int, ::Type{TestTag()}) = false
ForwardDiff.:≺(::Type{TestTag}, ::Type{OuterTestTag}) = true
ForwardDiff.:≺(::Type{OuterTestTag}, ::Type{TestTag}) = false

for N in (0,3), M in (0,4), V in (Int, Float32)
println(" ...testing Dual{TestTag(),$V,$N} and Dual{TestTag(),Dual{TestTag(),$V,$M},$N}")
Expand Down Expand Up @@ -553,6 +556,9 @@ end
@test pow(x3, 2) === x3^2 === x3 * x3
@test pow(x2, 1) === x2^1 === x2
@test pow(x1, 0) === x1^0 === Dual{:t1}(1.0, 0.0)
y = Dual{typeof(TestTag())}(1.0, 0.0, 1.0);
x = Dual{typeof(OuterTestTag())}(0*y, 0*y);
@test iszero(ForwardDiff.partials(ForwardDiff.partials(x^y)[1]))
end

@testset "Type min/max" begin
Expand Down