Add Diagonal[{T}](S::UniformScaling, n) constructors.

JuliaLang · Oct 31, 2017 · 64e3c08 · 64e3c08
1 parent 268f878
commit 64e3c08
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diff --git a/base/linalg/uniformscaling.jl b/base/linalg/uniformscaling.jl
@@ -353,3 +353,7 @@ UniformScaling{Float64}
 ```
 """
 chol(J::UniformScaling, args...) = ((C, info) = _chol!(J, nothing); @assertposdef C info)
+
+## Diagonal construction from UniformScaling
+Diagonal{T}(s::UniformScaling, m::Integer) where {T} = Diagonal{T}(fill(T(s.λ), m))
+Diagonal(s::UniformScaling, m::Integer) where {T} = Diagonal{eltype(s)}(s, m)
diff --git a/test/linalg/uniformscaling.jl b/test/linalg/uniformscaling.jl
@@ -189,3 +189,10 @@ end
         @test_throws LinAlg.PosDefException chol(-λ*I)
     end
 end
+
+@testset "Diagonal construction from UniformScaling" begin
+    @test Diagonal(2I, 3)::Diagonal{Int} == 2*eye(3)
+    @test Diagonal(2.0I, 3)::Diagonal{Float64} == 2*eye(3)
+    @test Diagonal{Real}(2I, 3)::Diagonal{Real} == 2*eye(3)
+    @test Diagonal{Float64}(2I, 3)::Diagonal{Float64} == 2*eye(3)
+end