kron for rectangular Eye

JuliaArrays · Jun 30, 2023 · 14a0423 · 14a0423
1 parent 8a13ebd
commit 14a0423
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Showing 3 changed files with 10 additions and 1 deletion.
diff --git a/src/FillArrays.jl b/src/FillArrays.jl
@@ -411,6 +411,7 @@ Base.replace_in_print_matrix(A::RectDiagonal, i::Integer, j::Integer, s::Abstrac
 
 
 const RectOrDiagonal{T,V,Axes} = Union{RectDiagonal{T,V,Axes}, Diagonal{T,V}}
+const RectDiagonalEye{T} = RectDiagonal{T,<:Ones{T,1}}
 const SquareEye{T,Axes} = Diagonal{T,Ones{T,1,Tuple{Axes}}}
 const Eye{T,Axes} = RectOrDiagonal{T,Ones{T,1,Tuple{Axes}}}
 

diff --git a/src/fillalgebra.jl b/src/fillalgebra.jl
@@ -453,3 +453,4 @@ function kron(f::AbstractFillVecOrMat, g::AbstractFillVecOrMat)
     sz = _kronsize(f, g)
     _kron(f, g, sz)
 end
+kron(E1::RectDiagonalEye, E2::RectDiagonalEye) = kron(sparse(E1), sparse(E2))
diff --git a/test/runtests.jl b/test/runtests.jl
@@ -1519,7 +1519,14 @@ end
     if VERSION >= v"1.9"
         @test K isa typeof(E)
     end
-    @test K == kron(collect(E), collect(E))
+    C = collect(E)
+    @test K == kron(C, C)
+
+    E = Eye(2,3)
+    K = kron(E, E)
+    C = collect(E)
+    @test K == kron(C, C)
+    @test issparse(kron(E,E))
 end
 
 @testset "dot products" begin