Support Symmetric(::BandedBlockBandedMatrix) (#128)

* Support Symmetric(::BandedBlockBandedMatrix)

* Revert "Update test_misc.jl"

This reverts commit 074293b.

* Fix HermitianLayout

Author: dlfivefifty

Project.toml

@@ -1,6 +1,6 @@
 name = "BlockBandedMatrices"
 uuid = "ffab5731-97b5-5995-9138-79e8c1846df0"
-version = "0.11.4"
+version = "0.11.5"
 
 [deps]
 ArrayLayouts = "4c555306-a7a7-4459-81d9-ec55ddd5c99a"
@@ -15,7 +15,7 @@ Statistics = "10745b16-79ce-11e8-11f9-7d13ad32a3b2"
 [compat]
 ArrayLayouts = "0.8.2"
 BandedMatrices = "0.16.8, 0.17"
-BlockArrays = "0.16.6"
+BlockArrays = "0.16.14"
 FillArrays = "0.13"
 MatrixFactorizations = "0.8.5, 0.9"
 julia = "1.6"

src/AbstractBlockBandedMatrix.jl

@@ -39,6 +39,21 @@ conjlayout(::Type{T}, ::BandedBlockBandedRows{Lay}) where {T<:Complex,Lay} = Ban
 conjlayout(::Type{T}, ::BlockBandedColumns{Lay}) where {T<:Complex,Lay} = BlockBandedColumns{typeof(conjlayout(T,Lay))}()
 conjlayout(::Type{T}, ::BlockBandedRows{Lay}) where {T<:Complex,Lay} = BlockBandedRows{typeof(conjlayout(T,Lay))}()
 
+symmetriclayout(::AbstractBandedBlockBandedLayout) = BandedBlockBandedLayout()
+hermitianlayout(_, ::AbstractBandedBlockBandedLayout) = BandedBlockBandedLayout()
+
+function blockbandwidths(S::HermOrSym)
+    l, u = blockbandwidths(parent(S))
+    if S.uplo == 'U'
+        (u, u)
+    else
+        (l, l)
+    end
+end
+function subblockbandwidths(S::HermOrSym)
+    m = max(subblockbandwidths(parent(S))...)
+    (m,m)
+end
 
 # AbstractBandedMatrix must implement
 

src/BlockBandedMatrices.jl

@@ -27,7 +27,7 @@ import ArrayLayouts: BlasMatLmulVec, MatLmulVec, MatLmulMat,
                     AbstractColumnMajor, DenseColumnMajor, ColumnMajor,
                     DiagonalLayout, MulAdd, mul, colsupport, rowsupport,
                     _qr, _factorize, _copyto!, zero!, layout_replace_in_print_matrix,
-                    transposelayout, conjlayout
+                    transposelayout, conjlayout, symmetriclayout, hermitianlayout
 
 import BlockArrays: blocksize, blockcheckbounds, BlockedUnitRange, blockisequal, DefaultBlockAxis,
                         Block, BlockSlice, unblock, block, blockindex,

test/test_bandedblockbanded.jl

@@ -516,6 +516,28 @@ import ArrayLayouts: RangeCumsum
         @test convert(AbstractArray{Float64}, A) == convert(AbstractMatrix{Float64}, A) == A
         @test convert(AbstractArray{Int}, A) ≡ convert(AbstractMatrix{Int}, A) ≡ A
     end
+
+    @testset "Symmetric" begin
+        l, u = 2, 1
+        λ, μ = 2, 1
+        N = M = 4
+        cols = rows = 1:N
+        data = reshape(collect(1:(λ+μ+1)*(l+u+1)*sum(cols)), ((λ + μ + 1) * (l + u + 1), sum(cols)))
+        A = _BandedBlockBandedMatrix(data, rows, cols, (l, u), (λ, μ))
+        
+        @test blockbandwidths(Hermitian(A)) == blockbandwidths(Symmetric(A)) == (1,1)
+        @test blockbandwidths(Hermitian(A,:L)) == blockbandwidths(Symmetric(A,:L)) == (2,2)
+        @test subblockbandwidths(Hermitian(A)) == subblockbandwidths(Symmetric(A)) == (2,2)
+        @test subblockbandwidths(Hermitian(A,:L)) == subblockbandwidths(Symmetric(A,:L)) == (2,2)
+
+        @test BandedBlockBandedMatrix(Symmetric(A)) == Symmetric(Matrix(A))
+        @test BandedBlockBandedMatrix(Symmetric(A,:L)) == Symmetric(Matrix(A),:L)
+        @test BandedBlockBandedMatrix(Hermitian(A)) == Hermitian(Matrix(A))
+        @test BandedBlockBandedMatrix(Hermitian(A,:L)) == Hermitian(Matrix(A),:L)
+
+        @test Symmetric(A)[Block.(1:3),Block.(1:3)] isa BandedBlockBandedMatrix
+        @test Hermitian(A)[Block.(1:3),Block.(1:3)] isa BandedBlockBandedMatrix
+    end
 end
 
 if false # turned off since tests have check-bounds=yes

test/test_misc.jl

@@ -160,18 +160,18 @@ end
     @testset "Block-BandedMatrix" begin
         a = blockedrange(1:5)
         B = _BandedMatrix(PseudoBlockArray(randn(5,length(a)),(Base.OneTo(5),a)), a, 3, 1)
-        @test blockcolsupport(B,Block(1)) == Block.(1:3)
-        @test blockcolsupport(B,Block(3)) == Block.(2:4)
-        @test blockrowsupport(B,Block(1)) == Block.(1:2)
-        @test blockrowsupport(B,Block(4)) == Block.(3:5)
+        @test blockcolsupport(B,1) == Block.(1:3)
+        @test blockcolsupport(B,3) == Block.(2:4)
+        @test blockrowsupport(B,1) == Block.(1:2)
+        @test blockrowsupport(B,4) == Block.(3:5)
 
         Q = Eye((a,))[:,Block(2)]
         @test Q isa BandedMatrix
-        @test blockcolsupport(Q,Block(1)) == Block.(2:2)
+        @test blockcolsupport(Q,1) == Block.(2:2)
 
         Q = Eye((a,))[Block(2),:]
         @test Q isa BandedMatrix
-        @test blockrowsupport(Q,Block(1)) == Block.(2:2)
+        @test blockrowsupport(Q,1) == Block.(2:2)
 
         @testset "constant blocks" begin
             a = blockedrange(Fill(2,5))