JuliaApproximation / JuliaApproximation/FastTransforms.jl
`cheb2ultra` seems unreasonably slow
Open
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- Dominant language
- Julia
- Stars
- 281
- Forks
- 27
- PR merge metrics
- No merged PRs in 30d
Description
julia> x = rand(1000);
julia> y1 = @btime FastTransforms.cheb2ultra($x, 2);
24.224 ms (2 allocations: 7.98 KiB)
julia> y2 = @btime ApproxFunBase.mul_coefficients(Conversion(Chebyshev(), Ultraspherical(2)), $x);
45.568 μs (13 allocations: 63.27 KiB)
julia> y1 ≈ y2
true
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Research direction
Start by reproducing the Julia benchmark comparing FastTransforms.cheb2ultra(x, 2) with ApproxFunBase.mul_coefficients for a length-1000 random vector. Investigate the implementation or entry point for cheb2ultra and preserve the observed numerical equivalence while addressing the reported performance gap.
Written by the indexing model from the issue text.
Assessment
- Tech stack
- julia
- Domain
- performance
- Issue type
- Bug
- Difficulty
- 3/5
- Estimated time
- 1-2 days
- Activity status
- Stale
- Clarity
- Mostly clear
- Newbie friendliness
- 35/100