Bandwidths tuple in view (#368)

Author: jishnub

Project.toml

@@ -1,6 +1,6 @@
 name = "ApproxFunBase"
 uuid = "fbd15aa5-315a-5a7d-a8a4-24992e37be05"
-version = "0.7.67"
+version = "0.7.68"
 
 [deps]
 AbstractFFTs = "621f4979-c628-5d54-868e-fcf4e3e8185c"
@@ -41,6 +41,7 @@ FFTW = "0.3, 1"
 FillArrays = "0.11, 0.12, 0.13"
 InfiniteArrays = "0.11, 0.12"
 InfiniteLinearAlgebra = "0.5, 0.6"
+Infinities = "0.1"
 IntervalSets = "0.5, 0.6, 0.7"
 LazyArrays = "0.20, 0.21, 0.22"
 LowRankApprox = "0.2, 0.3, 0.4, 0.5"
@@ -50,7 +51,8 @@ julia = "1.6"
 
 [extras]
 Aqua = "4c88cf16-eb10-579e-8560-4a9242c79595"
+Infinities = "e1ba4f0e-776d-440f-acd9-e1d2e9742647"
 Random = "9a3f8284-a2c9-5f02-9a11-845980a1fd5c"
 
 [targets]
-test = ["Aqua", "Random"]
+test = ["Aqua", "Random", "Infinities"]

src/Operators/SubOperator.jl

@@ -87,11 +87,16 @@ function view(A::Operator,kr::InfRanges,jr::InfRanges)
     if isbanded(A) && st==step(jr)  # Otherwise, its not a banded operator
         kr1=first(kr)
         jr1=first(jr)
-        l,u=(bandwidth(A,1)+jr1-kr1)÷st,(bandwidth(A,2)+kr1-jr1)÷st
+        shft = kr1-jr1
+        # working on the whole bandwidths tuple instead of
+        # the individual bandwidths helps with type-inference,
+        # e.g. if the bandwidth is inferred as
+        # Union{NTuple{2,InfiniteCardinal{0}}, NTuple{2,Int}}
+        bw = map(x -> x ÷ st, map(+, bandwidths(A), (-shft,shft)))
     else
-        l,u=ℵ₀,ℵ₀
+        bw=(ℵ₀,ℵ₀)
     end
-    SubOperator(A,(kr,jr),size(A),(l,u))
+    SubOperator(A,(kr,jr),size(A),bw)
 end
 
 view(V::SubOperator, kr::AbstractRange, jr::AbstractRange) =
@@ -102,8 +107,13 @@ function view(A::Operator, kr::AbstractRange, jr::AbstractRange)
     if isbanded(A) && st == step(jr)
         kr1=first(kr)
         jr1=first(jr)
-        l,u=(bandwidth(A,1)+jr1-kr1)÷st,(bandwidth(A,2)+kr1-jr1)÷st
-        SubOperator(A,(kr,jr),(length(kr),length(jr)),(l,u))
+        shft = kr1-jr1
+        # working on the whole bandwidths tuple instead of
+        # the individual bandwidths helps with type-inference,
+        # e.g. if the bandwidth is inferred as
+        # Union{NTuple{2,InfiniteCardinal{0}}, NTuple{2,Int}}
+        bw = map(x -> x ÷ st, map(+, bandwidths(A), (-shft,shft)))
+        SubOperator(A,(kr,jr),(length(kr),length(jr)),bw)
     else
         SubOperator(A,(kr,jr))
     end
@@ -113,8 +123,12 @@ end
 function view(A::Operator,kr::UnitRange,jr::UnitRange)
     if isbanded(A)
         shft=first(kr)-first(jr)
-        l,u=bandwidth(A,1)-shft,bandwidth(A,2)+shft
-        SubOperator(A,(kr,jr),(length(kr),length(jr)),(l,u))
+        # working on the whole bandwidths tuple instead of
+        # the individual bandwidths helps with type-inference,
+        # e.g. if the bandwidth is inferred as
+        # Union{NTuple{2,InfiniteCardinal{0}}, NTuple{2,Int}}
+        bw = map(+, bandwidths(A), (-shft,shft))
+        SubOperator(A,(kr,jr),(length(kr),length(jr)),bw)
     else
         SubOperator(A,(kr,jr))
     end

test/runtests.jl

@@ -1,9 +1,15 @@
-using ApproxFunBase, LinearAlgebra, Random, Test
+using ApproxFunBase
 using ApproxFunBase: ∞
 using Aqua
-using SpecialFunctions
 using BandedMatrices
+using DomainSets
 using FillArrays
+using InfiniteArrays
+using Infinities
+using LinearAlgebra
+using Random
+using SpecialFunctions
+using Test
 
 @testset "Project quality" begin
     Aqua.test_all(ApproxFunBase, ambiguities=false)
@@ -474,6 +480,17 @@ end
     A = @inferred ApproxFunBase.SymToeplitzOperator(Int[])
     B = A[1:5, 1:5]
     @test all(iszero, B)
+
+    @testset "kronecker type stability" begin
+        T = ApproxFunBase.ToeplitzOperator(Float64[1,2], Float64[1,2])
+        TT = T ⊗ T
+        TypeExp = Union{ApproxFunBase.SubOperator{Float64, KroneckerOperator{ToeplitzOperator{Float64}, ToeplitzOperator{Float64}, TensorSpace{Tuple{SequenceSpace, SequenceSpace}, DomainSets.VcatDomain{2, Int64, (1, 1), Tuple{ApproxFunBase.PositiveIntegers, ApproxFunBase.PositiveIntegers}}, Union{}}, TensorSpace{Tuple{SequenceSpace, SequenceSpace}, DomainSets.VcatDomain{2, Int64, (1, 1), Tuple{ApproxFunBase.PositiveIntegers, ApproxFunBase.PositiveIntegers}}, Union{}}, ApproxFunBase.CachedIterator{Tuple{Int64, Int64}, ApproxFunBase.Tensorizer{Tuple{FillArrays.Ones{Int64, 1, Tuple{InfiniteArrays.OneToInf{Int64}}}, FillArrays.Ones{Int64, 1, Tuple{InfiniteArrays.OneToInf{Int64}}}}}}, ApproxFunBase.CachedIterator{Tuple{Int64, Int64}, ApproxFunBase.Tensorizer{Tuple{FillArrays.Ones{Int64, 1, Tuple{InfiniteArrays.OneToInf{Int64}}}, FillArrays.Ones{Int64, 1, Tuple{InfiniteArrays.OneToInf{Int64}}}}}}, Float64}, Tuple{UnitRange{Int64}, UnitRange{Int64}}, Tuple{Int64, Int64}, Tuple{Infinities.InfiniteCardinal{0}, Infinities.InfiniteCardinal{0}}}, ApproxFunBase.SubOperator{Float64, KroneckerOperator{ToeplitzOperator{Float64}, ToeplitzOperator{Float64}, TensorSpace{Tuple{SequenceSpace, SequenceSpace}, DomainSets.VcatDomain{2, Int64, (1, 1), Tuple{ApproxFunBase.PositiveIntegers, ApproxFunBase.PositiveIntegers}}, Union{}}, TensorSpace{Tuple{SequenceSpace, SequenceSpace}, DomainSets.VcatDomain{2, Int64, (1, 1), Tuple{ApproxFunBase.PositiveIntegers, ApproxFunBase.PositiveIntegers}}, Union{}}, ApproxFunBase.CachedIterator{Tuple{Int64, Int64}, ApproxFunBase.Tensorizer{Tuple{FillArrays.Ones{Int64, 1, Tuple{InfiniteArrays.OneToInf{Int64}}}, FillArrays.Ones{Int64, 1, Tuple{InfiniteArrays.OneToInf{Int64}}}}}}, ApproxFunBase.CachedIterator{Tuple{Int64, Int64}, ApproxFunBase.Tensorizer{Tuple{FillArrays.Ones{Int64, 1, Tuple{InfiniteArrays.OneToInf{Int64}}}, FillArrays.Ones{Int64, 1, Tuple{InfiniteArrays.OneToInf{Int64}}}}}}, Float64}, Tuple{UnitRange{Int64}, UnitRange{Int64}}, Tuple{Int64, Int64}, Tuple{Int64, Int64}}}
+        @inferred TypeExp view(T, 1:1, 1:1)
+        TypeExp2 = Union{ApproxFunBase.SubOperator{Float64, KroneckerOperator{ToeplitzOperator{Float64}, ToeplitzOperator{Float64}, TensorSpace{Tuple{SequenceSpace, SequenceSpace}, DomainSets.VcatDomain{2, Int64, (1, 1), Tuple{ApproxFunBase.PositiveIntegers, ApproxFunBase.PositiveIntegers}}, Union{}}, TensorSpace{Tuple{SequenceSpace, SequenceSpace}, DomainSets.VcatDomain{2, Int64, (1, 1), Tuple{ApproxFunBase.PositiveIntegers, ApproxFunBase.PositiveIntegers}}, Union{}}, ApproxFunBase.CachedIterator{Tuple{Int64, Int64}, ApproxFunBase.Tensorizer{Tuple{FillArrays.Ones{Int64, 1, Tuple{InfiniteArrays.OneToInf{Int64}}}, FillArrays.Ones{Int64, 1, Tuple{InfiniteArrays.OneToInf{Int64}}}}}}, ApproxFunBase.CachedIterator{Tuple{Int64, Int64}, ApproxFunBase.Tensorizer{Tuple{FillArrays.Ones{Int64, 1, Tuple{InfiniteArrays.OneToInf{Int64}}}, FillArrays.Ones{Int64, 1, Tuple{InfiniteArrays.OneToInf{Int64}}}}}}, Float64}, Tuple{StepRange{Int64, Int64}, StepRange{Int64, Int64}}, Tuple{Int64, Int64}, Tuple{Infinities.InfiniteCardinal{0}, Infinities.InfiniteCardinal{0}}}, ApproxFunBase.SubOperator{Float64, KroneckerOperator{ToeplitzOperator{Float64}, ToeplitzOperator{Float64}, TensorSpace{Tuple{SequenceSpace, SequenceSpace}, DomainSets.VcatDomain{2, Int64, (1, 1), Tuple{ApproxFunBase.PositiveIntegers, ApproxFunBase.PositiveIntegers}}, Union{}}, TensorSpace{Tuple{SequenceSpace, SequenceSpace}, DomainSets.VcatDomain{2, Int64, (1, 1), Tuple{ApproxFunBase.PositiveIntegers, ApproxFunBase.PositiveIntegers}}, Union{}}, ApproxFunBase.CachedIterator{Tuple{Int64, Int64}, ApproxFunBase.Tensorizer{Tuple{FillArrays.Ones{Int64, 1, Tuple{InfiniteArrays.OneToInf{Int64}}}, FillArrays.Ones{Int64, 1, Tuple{InfiniteArrays.OneToInf{Int64}}}}}}, ApproxFunBase.CachedIterator{Tuple{Int64, Int64}, ApproxFunBase.Tensorizer{Tuple{FillArrays.Ones{Int64, 1, Tuple{InfiniteArrays.OneToInf{Int64}}}, FillArrays.Ones{Int64, 1, Tuple{InfiniteArrays.OneToInf{Int64}}}}}}, Float64}, Tuple{StepRange{Int64, Int64}, StepRange{Int64, Int64}}, Tuple{Int64, Int64}, Tuple{Int64, Int64}}}
+        @inferred TypeExp2 view(T, 1:1:1, 1:1:1)
+        TypeExp3 = Union{ApproxFunBase.SubOperator{Float64, KroneckerOperator{ToeplitzOperator{Float64}, ToeplitzOperator{Float64}, TensorSpace{Tuple{SequenceSpace, SequenceSpace}, DomainSets.VcatDomain{2, Int64, (1, 1), Tuple{ApproxFunBase.PositiveIntegers, ApproxFunBase.PositiveIntegers}}, Union{}}, TensorSpace{Tuple{SequenceSpace, SequenceSpace}, DomainSets.VcatDomain{2, Int64, (1, 1), Tuple{ApproxFunBase.PositiveIntegers, ApproxFunBase.PositiveIntegers}}, Union{}}, ApproxFunBase.CachedIterator{Tuple{Int64, Int64}, ApproxFunBase.Tensorizer{Tuple{Ones{Int64, 1, Tuple{InfiniteArrays.OneToInf{Int64}}}, Ones{Int64, 1, Tuple{InfiniteArrays.OneToInf{Int64}}}}}}, ApproxFunBase.CachedIterator{Tuple{Int64, Int64}, ApproxFunBase.Tensorizer{Tuple{Ones{Int64, 1, Tuple{InfiniteArrays.OneToInf{Int64}}}, Ones{Int64, 1, Tuple{InfiniteArrays.OneToInf{Int64}}}}}}, Float64}, Tuple{InfiniteArrays.InfUnitRange{Int64}, InfiniteArrays.InfUnitRange{Int64}}, Tuple{Infinities.Infinity, Infinities.Infinity}, Tuple{Infinities.InfiniteCardinal{0}, Infinities.InfiniteCardinal{0}}}, ApproxFunBase.SubOperator{Float64, KroneckerOperator{ToeplitzOperator{Float64}, ToeplitzOperator{Float64}, TensorSpace{Tuple{SequenceSpace, SequenceSpace}, DomainSets.VcatDomain{2, Int64, (1, 1), Tuple{ApproxFunBase.PositiveIntegers, ApproxFunBase.PositiveIntegers}}, Union{}}, TensorSpace{Tuple{SequenceSpace, SequenceSpace}, DomainSets.VcatDomain{2, Int64, (1, 1), Tuple{ApproxFunBase.PositiveIntegers, ApproxFunBase.PositiveIntegers}}, Union{}}, ApproxFunBase.CachedIterator{Tuple{Int64, Int64}, ApproxFunBase.Tensorizer{Tuple{Ones{Int64, 1, Tuple{InfiniteArrays.OneToInf{Int64}}}, Ones{Int64, 1, Tuple{InfiniteArrays.OneToInf{Int64}}}}}}, ApproxFunBase.CachedIterator{Tuple{Int64, Int64}, ApproxFunBase.Tensorizer{Tuple{Ones{Int64, 1, Tuple{InfiniteArrays.OneToInf{Int64}}}, Ones{Int64, 1, Tuple{InfiniteArrays.OneToInf{Int64}}}}}}, Float64}, Tuple{InfiniteArrays.InfUnitRange{Int64}, InfiniteArrays.InfUnitRange{Int64}}, Tuple{Infinities.Infinity, Infinities.Infinity}, Tuple{Int64, Int64}}}
+        @inferred TypeExp3 view(T, 1:∞, 1:∞)
+    end
 end
 
 @testset "Tensorizer" begin