JuliaDiff / JuliaDiff/ForwardDiff.jl
Perturbation Confusion issue
Open
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- Dominant language
- Julia
- Stars
- 1k
- Forks
- 160
- PR merge metrics
- No merged PRs in 30d
Description
D(f, x) = ForwardDiff.derivative(f, x)
D(1) do x
f(y) = (x = x*y)
D(f, 1)
D(f, 1)
end # => 2
The correct answer is 1. This is essentially the same as https://github.com/YingboMa/ForwardDiff2.jl/issues/37.
Contributor guide
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First steps
- Read the whole issue, then the project's contributing guide.
- Comment on the issue to say you are picking it up — it saves two people doing the same work.
- Fork the repository and make your change on a branch.
- Open a pull request that references the issue number.
Research direction
Run the Julia reproducer using ForwardDiff.derivative and compare the behavior with the linked ForwardDiff2.jl issue. Trace how nested derivative calls handle perturbations, then verify that the example returns 1 and add regression coverage for the repeated derivative calls.
Written by the indexing model from the issue text.
Assessment
- Tech stack
- julia
- Domain
- tooling
- Issue type
- Bug
- Difficulty
- 4/5
- Estimated time
- 3-5 days
- Activity status
- Stale
- Clarity
- Mostly clear
- Newbie friendliness
- 35/100