bandwidth info

Author: dlfivefifty

src/InfiniteLinearAlgebra.jl

@@ -8,7 +8,7 @@ import Base.Broadcast: BroadcastStyle
 
 import InfiniteArrays: OneToInf, InfUnitRange, Infinity, InfStepRange
 import FillArrays: AbstractFill
-import BandedMatrices: BandedMatrix, _BandedMatrix, bandeddata
+import BandedMatrices: BandedMatrix, _BandedMatrix, bandeddata, bandwidths
 import LinearAlgebra: lmul!,  ldiv!, matprod, qr, AbstractTriangular, AbstractQ, adjoint, transpose
 import LazyArrays: CachedArray, DenseColumnMajor, FillLayout, ApplyMatrix, check_mul_axes, ApplyStyle, LazyArrayApplyStyle, LazyArrayStyle,
                     CachedMatrix, CachedArray, resizedata!, MemoryLayout

src/infqr.jl

@@ -35,6 +35,7 @@ struct AdaptiveQRFactors{T,DM<:AbstractMatrix{T},M<:AbstractMatrix{T}} <: Abstra
 end
 
 size(F::AdaptiveQRFactors) = size(F.data.data)
+bandwidths(F::AdaptiveQRFactors) = bandwidths(F.data.data)
 function getindex(F::AdaptiveQRFactors, k::Int, j::Int)
     partialqr!(F.data, j)
     F.data.data[k,j]

test/runtests.jl

@@ -2,6 +2,7 @@ using InfiniteLinearAlgebra, BlockBandedMatrices, BlockArrays, BandedMatrices, I
 import InfiniteLinearAlgebra: qltail, toeptail, tailiterate , tailiterate!, tail_de, ql_X!,
                     InfToeplitz, PertToeplitz, TriToeplitz, InfBandedMatrix, 
                     rightasymptotics, QLHessenberg
+import BlockArrays: _BlockArray                    
 import BlockBandedMatrices: isblockbanded, _BlockBandedMatrix
 import MatrixFactorizations: QLPackedQ
 import BandedMatrices: bandeddata, _BandedMatrix
@@ -45,6 +46,15 @@ import BandedMatrices: bandeddata, _BandedMatrix
     @test A*A isa ApplyArray
     @test (A^2)[1:10,1:10] == (A*A)[1:10,1:10] == (A[1:100,1:100]^2)[1:10,1:10]
     @test (A^3)[1:10,1:10] == (A*A*A)[1:10,1:10] == (A[1:100,1:100]^3)[1:10,1:10]
+
+    @testset "Triangle OP recurrences" begin
+        mortar((n -> 1:n).(1:∞))
+    end
+    # Multivariate OPs Corollary (3)
+    # n = 5
+    # BlockTridiagonal(Zeros.(1:∞,2:∞),
+    #         (n -> Diagonal(((n+2).+(0:n)))/ (2n + 2)).(0:∞),
+    #         Zeros.(2:∞,1:∞))
 end
 
 include("test_hessenbergq.jl")

test/test_infqr.jl

@@ -31,7 +31,9 @@ import InfiniteLinearAlgebra: partialqr!, AdaptiveQRData
         @test F.τ[1] ≈ 1+sqrt(2)/2
         @test F.τ[100] ≈ qrunblocked(A[1:101,1:100]).τ[100]
         Q,R = F;
-        
+        @test bandwidths(R) == (0,2)
+        @test size(R) == (∞,∞)
+        @test R[1,1] == -sqrt(2)
     end
 end