JuliaAstro / JuliaAstro/SpectralFitting.jl

Derivatives w.r.t. a particular parameter

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Dominant language
Julia
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22
Forks
11
Avg merge
1d 10h
Merged PRs (30d)
2

Description

If a parameter does not affect a particular component of the model, there is no point evaluating it again to obtain the derivative of the overall model. That is, for some a1 + a2 model, imagine wanting the derivative of the output w.r.t a1.p1. Then under the hood, the last output of a2 should be cached (provided no other parameters were altered). I suppose this is the equivalent of putting AutoCache on everything?

Alternatively, the derivative of f(x) + c w.r.t x is just f'(x), so additive components around the model can be ignored without it changing the result of the derivative.

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Research direction

No files, tests, or entry points are named. Start by tracing how derivatives are evaluated for additive model components, then determine how cached outputs remain valid when unrelated parameters change; done means unaffected components are not reevaluated while the derivative remains correct.

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Assessment

Tech stack
julia
Domain
data
Issue type
Feature
Difficulty
5/5
Estimated time
Over a week
Activity status
Stale
Clarity
Mostly clear
Newbie friendliness
32/100

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