Support RectDiagonal (#411)

Author: dlfivefifty

Project.toml

@@ -1,6 +1,6 @@
 name = "BandedMatrices"
 uuid = "aae01518-5342-5314-be14-df237901396f"
-version = "1.2.1"
+version = "1.3"
 
 [deps]
 ArrayLayouts = "4c555306-a7a7-4459-81d9-ec55ddd5c99a"

src/BandedMatrices.jl

@@ -34,7 +34,7 @@ import ArrayLayouts: MemoryLayout, transposelayout, triangulardata,
                     _qr!, _qr, _lu!, _lu, _factorize, AbstractTridiagonalLayout, TridiagonalLayout,
                     BidiagonalLayout, bidiagonaluplo, diagonaldata, supdiagonaldata, subdiagonaldata, copymutable_oftype_layout, dualadjoint
 
-import FillArrays: AbstractFill, getindex_value, _broadcasted_zeros, unique_value, OneElement
+import FillArrays: AbstractFill, getindex_value, _broadcasted_zeros, unique_value, OneElement, RectDiagonal
 
 const libblas = LinearAlgebra.BLAS.libblas
 const liblapack = LinearAlgebra.BLAS.liblapack

src/banded/BandedMatrix.jl

@@ -226,10 +226,10 @@ BandedMatrix{V,C,Base.OneTo{Int}}(Z::Zeros{T,2}, bnds::NTuple{2,Integer}) where
 BandedMatrix{V}(Z::Zeros{T,2}, bnds::NTuple{2,Integer}) where {T,V} =
     _BandedMatrix(zeros(V,max(0,sum(bnds)+1),size(Z,2)),size(Z,1),bnds...)
 
-BandedMatrix(E::Eye{T}, bnds::NTuple{2,Integer}) where T = BandedMatrix{T}(E, bnds)
-function BandedMatrix{T}(E::Eye, bnds::NTuple{2,Integer}) where T
-    ret=BandedMatrix(Zeros{T}(E), bnds)
-    ret[band(0)] .= one(T)
+BandedMatrix(E::RectDiagonal{T}, bnds::NTuple{2,Integer}) where T = BandedMatrix{T}(E, bnds)
+function BandedMatrix{T}(E::RectDiagonal, bnds::NTuple{2,Integer}) where T
+    ret = BandedMatrix(Zeros{T}(E), bnds)
+    ret[band(0)] .= E.diag
     ret
 end
 

src/interfaceimpl.jl

@@ -18,9 +18,9 @@ isbanded(::Zeros) = true
 bandwidths(::Zeros) = (-40320,-40320) # 40320 == prod(1:8), used for special cases involving gcd
 inbands_getindex(::Zeros{T}, k::Integer, j::Integer) where T = zero(T)
 
-isbanded(::Eye) = true
-bandwidths(::Eye) = (0,0)
-inbands_getindex(::Eye{T}, k::Integer, j::Integer) where T = one(T)
+isbanded(::RectDiagonal) = true
+bandwidths(::RectDiagonal) = (0,0)
+inbands_getindex(E::RectDiagonal, k::Integer, j::Integer) = E.diag[k]
 
 isbanded(::Diagonal) = true
 bandwidths(::Diagonal) = (0,0)

test/test_interface.jl

@@ -59,6 +59,10 @@ LinearAlgebra.fill!(A::PseudoBandedMatrix, v) = fill!(A.data,v)
         @test B * Eye(5) == B
         @test muladd!(2.0, Eye(5), B, 0.0, zeros(5,5)) == 2B
         @test muladd!(2.0, B, Eye(5), 0.0, zeros(5,5)) == 2B
+
+        @test isbanded(2Eye(5,6))
+        @test bandwidths(2Eye(5,6)) == (0,0)
+        @test BandedMatrices.inbands_getindex(2Eye(5,6), 1,1) == 2
     end
 
     @testset "Diagonal" begin