Fix scaled interpolation for Unitful ranges. (#490)

Author: contradict

src/scaling/scaling.jl

@@ -99,11 +99,11 @@ coordslookup(::Any, ::Tuple{}, ::Tuple{}) = ()
 coordlookup(::NoInterp, r, i) = i
 coordlookup(::Flag, r, x) = coordlookup(r, x)
 
-coordlookup(r::AbstractUnitRange, x) = x - first(r) + oneunit(eltype(r))
+coordlookup(r::AbstractUnitRange, x) = (x - first(r))/oneunit(eltype(r)) + one(eltype(r))
 # coordlookup(i::Bool, r::AbstractRange, x) = i ? coordlookup(r, x) : convert(typeof(coordlookup(r,x)), x)
-coordlookup(r::StepRange, x) = (x - r.start) / r.step + oneunit(eltype(r))
+coordlookup(r::StepRange, x) = (x - r.start) / r.step + one(eltype(r))
 
-coordlookup(r::AbstractRange, x) = (x - first(r)) / step(r) + oneunit(eltype(r))
+coordlookup(r::AbstractRange, x) = (x - first(r)) / step(r) + one(eltype(r))
 boundstep(r::AbstractRange) = 0.5*step(r)
 rescale_gradient(r::AbstractRange, g) = g / step(r)
 

test/scaling/runtests.jl

@@ -2,3 +2,4 @@ include("scaling.jl")
 include("dimspecs.jl")
 include("nointerp.jl")
 include("withextrap.jl")
+include("unitful.jl")

test/scaling/unitful.jl

@@ -0,0 +1,16 @@
+using Unitful
+
+@testset "Unitful scaled interpolation" begin
+    # Abstract range
+    Xs = (0:.2:5)u"m"
+    Ys = Xs .^ 2
+    sitp = scale(interpolate(Ys, BSpline(Quadratic(Free(OnGrid())))), Xs)
+    @test sitp.((0:1:3)u"cm") ≈ ((0:1:3)u"cm") .^ 2
+
+    # Step Range
+    Xss = (0:5)u"m"
+    Yss = Float64.(Xss .^ 2)
+    sitp = scale(interpolate(Yss, BSpline(Quadratic(Free(OnGrid())))), Xss)
+    @test sitp((0:1:3)u"cm") ≈ ((0:1:3)u"cm") .^ 2
+
+end