Support Banded * Strided (#408)

Author: dlfivefifty

Project.toml

@@ -1,6 +1,6 @@
 name = "BandedMatrices"
 uuid = "aae01518-5342-5314-be14-df237901396f"
-version = "1.2.0"
+version = "1.2.1"
 
 [deps]
 ArrayLayouts = "4c555306-a7a7-4459-81d9-ec55ddd5c99a"

src/generic/matmul.jl

@@ -239,7 +239,7 @@ end
 
 ### BandedMatrix * dense matrix
 
-function materialize!(M::MatMulMatAdd{<:BandedColumns, <:AbstractColumnMajor, <:AbstractColumnMajor})
+function materialize!(M::MatMulMatAdd{<:BandedColumns, <:AbstractStridedLayout, <:AbstractStridedLayout})
     checkdimensions(M)
     α, β, A, B, C = M.α, M.β, M.A, M.B, M.C
 
@@ -254,7 +254,7 @@ function materialize!(M::MatMulMatAdd{<:BandedColumns, <:AbstractColumnMajor, <:
     return C
 end
 
-function materialize!(M::MatMulMatAdd{<:AbstractColumnMajor, <:BandedColumns, <:AbstractColumnMajor})
+function materialize!(M::MatMulMatAdd{<:AbstractStridedLayout, <:BandedColumns, <:AbstractStridedLayout})
     checkdimensions(M)
     α, β, A, B, C = M.α, M.β, M.A, M.B, M.C
 

test/test_linalg.jl

@@ -1,8 +1,4 @@
-using ArrayLayouts
-using BandedMatrices
-using FillArrays
-using LinearAlgebra
-using Test
+using ArrayLayouts, BandedMatrices, FillArrays, LinearAlgebra, Test
 
 import Base.Broadcast: materialize, broadcasted
 import BandedMatrices: BandedColumns, _BandedMatrix
@@ -106,6 +102,13 @@ ArrayLayouts.colsupport(::UnknownLayout, A::MyOneElement{<:Any,1}, _) =
                 @test cmp(Y, BX + ones(T, size(Y)))
             end
         end
+        @testset "Banded * strided" begin
+            n = 100
+            B = BandedMatrix{Float64}(-1=>1:n, 1=>11:n+10, 2=>21:n+19)
+            M = view(randn(2n+1,2n+1),1:2:2n+1,1:2:2n+1)
+            @test B*M ≈ Matrix(B)*M
+            @test M*B ≈ M*Matrix(B)
+        end
     end
 
     @testset "BandedMatrix * sparse" begin