JuliaDiff / JuliaDiff/AbstractDifferentiation.jl

`lazy_jacobian` is less generic than `pullback_function`

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bug
Dominant language
Julia
Stars
138
Forks
18
PR merge metrics
No merged PRs in 30d

Description

The result J of lazy_jacobian can supposedly be used as v' * J for vector-Jacobian products, but the tranpose operator doesn't work if v is, for instance, a 3D array

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  2. Comment on the issue to say you are picking it up — it saves two people doing the same work.
  3. Fork the repository and make your change on a branch.
  4. Open a pull request that references the issue number.

Research direction

Start by locating the definitions of lazy_jacobian and pullback_function, then reproduce the reported v' * J case with a 3D array. Compare the two interfaces and determine what behavior is expected; done means vector-Jacobian products work for that input shape or the limitation is clearly resolved.

Written by the indexing model from the issue text.

Assessment

Tech stack
julia
Domain
backend-api-design
Issue type
Bug
Difficulty
4/5
Estimated time
3-5 days
Activity status
Stale
Clarity
Needs clarification
Newbie friendliness
30/100

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