Interlace coeffs by blocks in Fourier integrate (#86)

Author: jishnub

Project.toml

@@ -1,6 +1,6 @@
 name = "ApproxFunFourier"
 uuid = "59844689-9c9d-51bf-9583-5b794ec66d30"
-version = "0.3.16"
+version = "0.3.17"
 
 [deps]
 AbstractFFTs = "621f4979-c628-5d54-868e-fcf4e3e8185c"
@@ -17,7 +17,7 @@ StaticArrays = "90137ffa-7385-5640-81b9-e52037218182"
 
 [compat]
 AbstractFFTs = "0.5, 1"
-ApproxFunBase = "0.8.6"
+ApproxFunBase = "0.8.9"
 ApproxFunBaseTest = "0.1"
 ApproxFunOrthogonalPolynomials = "0.6"
 Aqua = "0.5"

src/ApproxFunFourier.jl

@@ -31,7 +31,7 @@ import ApproxFunBase: Fun, SumSpace, SubSpace, NoSpace, IntervalOrSegment,
             setcanonicaldomain, mappoint, reverseorientation, checkpoints,
             evaluate, mul_coefficients, coefficients, clenshaw, ClenshawPlan,
             sineshaw, toeplitz_getindex, ToeplitzOperator, hankel_getindex,
-            SpaceOperator, ZeroOperator, InterlaceOperator, interlace!,
+            SpaceOperator, ZeroOperator, InterlaceOperator, interlace!, interlace,
             reverseeven!, negateeven!, cfstype, alternatesign!, extremal_args,
             hesseneigvals, chebyshev_clenshaw, roots, EmptyDomain,
             chebmult_getindex, components, affine_setdiff, complexroots,

src/calculus.jl

@@ -81,7 +81,7 @@ function integrate(f::Fun{CS}) where CS<:CosSpace
             fconstant = (f.coefficients[1]*x)
             fperiodic = integrate(Fun(f,space(f)|(2:∞)))
             SS = SumSpace(space(fconstant), space(fperiodic))
-            Fun(SS, ApproxFunBase.interlace(coefficients(fconstant), coefficients(fperiodic)))
+            Fun(SS, interlace(coefficients(fconstant), coefficients(fperiodic)))
         else
             throw(ArgumentError("not implemented"))
         end
@@ -107,8 +107,11 @@ function integrate(f::Fun{Fourier{D,R},T}) where {T,D<:PeriodicSegment,R}
     g1 = integrate(component(f,2))
     g2 = integrate(component(f,1))
     # g1 ⊕ g2, but we construct the space directly to improve type-stability
-    SS = SumSpace(space(g1), space(g2))
-    Fun(SS, ApproxFunBase.interlace(coefficients(g1), coefficients(g2)))
+    S1 = space(g1)
+    S2 = space(g2)
+    SS = SumSpace(S1, S2)
+    nc = map(ncomponents, (S1,S2))
+    Fun(SS, interlace(coefficients(g1), coefficients(g2), nc))
 end
 
 

test/runtests.jl

@@ -301,11 +301,13 @@ end
         @test norm(integrate(f)'-f)<10eps()
     end
     @test iszero(integrate(Fun(CosSpace(), Float64[])))
-    f = Fun(θ->1+cos(θ), CosSpace())
-    g = integrate(f)
-    θ = 0.4
-    @test g(θ) ≈ θ + sin(θ)
-    @test Fun(g', space(f)) ≈ f
+    for S in (CosSpace(), Fourier())
+        f = Fun(θ->1+cos(θ), S)
+        g = integrate(f)
+        θ = 0.4
+        @test g(θ) ≈ θ + sin(θ)
+        @test Fun(g', S) ≈ f
+    end
 end