JuliaDiff / JuliaDiff/DifferentiationInterface.jl
convert active argument in case of a preparation mismatch
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- Dominant language
- Julia
- Stars
- 313
- Forks
- 35
- PR merge metrics
- No merged PRs in 30d
Description
I understand that the argument type has to match the prepared backend. However, instead of erroring, in some situations it would make sense to just convert to the right type. Eg in the example below, the last line could work, in accordance with the robustness principle (with the understanding that it allocates, is suboptimal, etc).
julia> import ForwardDiff
julia> import DifferentiationInterface as DI
julia> backend = DI.AutoForwardDiff()
AutoForwardDiff()
julia> test(x) = x .+ 1
test (generic function with 2 methods)
julia> x = ones(3);
julia> prep = prepare_jacobian(test, backend, x);
julia> DI.value_and_jacobian(test, prep, backend, x)
([2.0, 2.0, 2.0], [1.0 0.0 0.0; 0.0 1.0 0.0; 0.0 0.0 1.0])
julia> DI.value_and_jacobian(test, prep, backend, Float32.(x))
ERROR: PreparationMismatchError (inconsistent types between preparation and execution):
- f: ✅
- backend: ✅
- x: ❌
- prep: Vector{Float64}
- exec: Vector{Float32}
- contexts: ✅
If you are confident that this check is superfluous, you can disable it by running preparation with the keyword argument `strict=Val(false)` inside DifferentiationInterface.
I would allow this always, but I understand that some users would just want to catch this performance issue as an error. So maybe an option, or a wrapper-like API
DI.value_and_jacobian(test, prep, backend, AutoConvert(Float32.(x)))
would make sense.
Contributor guide
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
Start by reading the prepare_jacobian and value_and_jacobian entry points shown in the issue, along with the PreparationMismatchError behavior. Compare the proposed automatic conversion with the strict preparation check and the suggested AutoConvert wrapper. Done means the project has a decided API and behavior for handling compatible type mismatches.
Written by the indexing model from the issue text.
Assessment
- Tech stack
- julia
- Domain
- backend-api-design
- Issue type
- Feature
- Difficulty
- 5/5
- Estimated time
- Over a week
- Activity status
- Stale
- Clarity
- Mostly clear
- Newbie friendliness
- 35/100