Support for Unitful.jl integrands

[juliohm]

It seems the units are ignored/stripped somewhere in the Backend.Quadrature.

[juliohm]

I've updated the PR in Meshes.jl with the master branch of II: JuliaGeometry/Meshes.jl#1327

If you try to run the first test with Box1D, you get the following unit error:

using Meshes
using Unitful

b = Box((0,), (π,))
function f(p)
  x = only(ustrip.(to(p)))
  √(π^2 - x^2) * u"A"
end
Meshes.integral(f, b)

ERROR: DimensionError: 0.0 and 2.724089968029507 A m are not dimensionally compatible.
Stacktrace:
 [1] +(x::Quantity{Float64, NoDims, Unitful.FreeUnits{…}}, y::Quantity{Float64, 𝐈 𝐋, Unitful.FreeUnits{…}})
   @ Unitful ~/.julia/packages/Unitful/HhRY9/src/quantities.jl:137
 [2] +(x::Float64, y::Quantity{Float64, 𝐈 𝐋, Unitful.FreeUnits{(A, m), 𝐈 𝐋, nothing}})
   @ Base ./promotion.jl:433
 [3] add_sum(x::Float64, y::Quantity{Float64, 𝐈 𝐋, Unitful.FreeUnits{(A, m), 𝐈 𝐋, nothing}})
   @ Base ./reduce.jl:16
 [4] BottomRF
   @ ./reduce.jl:78 [inlined]
 [5] MappingRF (repeats 2 times)
   @ ./reduce.jl:92 [inlined]
 [6] _foldl_impl(op::Base.MappingRF{…}, init::Float64, itr::Base.Iterators.Zip{…})
   @ Base ./reduce.jl:50
 [7] localintegral(fun::ComposedFunction{…}, geom::Box{…}, method::IntegrationInterface.Backend.Quadrature)
   @ Meshes ~/.julia/dev/Meshes/src/integration.jl:59

[pablosanjose]

I plan to look into this tomorrow after lunch at the latest.

[pablosanjose]

It turned out to be simpler than I thought, see #24. Will merge straight away as soon as CI passes, please try it with Meshes.jl again and report back if things still fail.

[juliohm]

Thank you @pablosanjose , I confirm the issue was fixed. Updated the tests in JuliaGeometry/Meshes.jl#1333

I'm experiencing new issues with multivariate integrands, which I will report next.