JuliaApproximation / JuliaApproximation/ApproxFun.jl

cumsum error

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Dominant language
Julia
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Forks
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Description

I'm just trying to make a function for the arclength along a space-curve.

curve(u) = [1.,0.,cos(u)]
dist = arclength(curve)
speed = Fun(u->hypot(derivative(curve,u)...),0..pi)
sum(speed) # 2.0 works!
cumsum(speed)(pi) # 0.0 doesn't work!

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Research direction

Reproduce the Julia snippet in an ApproxFun.jl environment, beginning with the cumsum(speed)(pi) call and the implementation or tests for cumsum on Fun values. Compare its result with the working sum(speed) calculation; done means cumulative evaluation at pi returns the expected arc-length value without breaking existing cumsum behavior.

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Assessment

Tech stack
julia
Domain
backend
Issue type
Bug
Difficulty
3/5
Estimated time
1-2 days
Activity status
Stale
Clarity
Mostly clear
Newbie friendliness
45/100

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