Implement isdiag(::Bidiagonal), add tests (#32694)

(cherry picked from commit 25eb8c6)
JuliaLang · Aug 5, 2019 · 5f4a567 · 5f4a567
1 parent 74312a0
commit 5f4a567
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diff --git a/stdlib/LinearAlgebra/src/bidiag.jl b/stdlib/LinearAlgebra/src/bidiag.jl
@@ -248,6 +248,7 @@ iszero(M::Bidiagonal) = iszero(M.dv) && iszero(M.ev)
 isone(M::Bidiagonal) = all(isone, M.dv) && iszero(M.ev)
 istriu(M::Bidiagonal) = M.uplo == 'U' || iszero(M.ev)
 istril(M::Bidiagonal) = M.uplo == 'L' || iszero(M.ev)
+isdiag(M::Bidiagonal) = iszero(M.ev)
 
 function tril!(M::Bidiagonal, k::Integer=0)
  n = length(M.dv)

diff --git a/stdlib/LinearAlgebra/test/bidiag.jl b/stdlib/LinearAlgebra/test/bidiag.jl
@@ -150,6 +150,10 @@ Random.seed!(1)
  @test triu!(bidiagcopy(dv,ev,:U)) == Bidiagonal(dv,ev,:U)
  @test_throws ArgumentError triu!(bidiagcopy(dv, ev, :U), -n)
  @test_throws ArgumentError triu!(bidiagcopy(dv, ev, :U), n + 2)
+ @test !isdiag(Bidiagonal(dv,ev,:U))
+ @test !isdiag(Bidiagonal(dv,ev,:L))
+ @test isdiag(Bidiagonal(dv,zerosev,:U))
+ @test isdiag(Bidiagonal(dv,zerosev,:L))
  end
 
  @testset "iszero and isone" begin