Merge pull request JuliaLang#14231 from cpk26/sparse-matrix

Add unary - for Symmetric
halleysfifthinc · Dec 7, 2015 · a949baf · a949baf
2 parents 60f46ca + 28a2dfa
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diff --git a/base/linalg/symmetric.jl b/base/linalg/symmetric.jl
@@ -105,6 +105,8 @@ function triu(A::Symmetric, k::Integer=0)
  end
 end
 
+-{Tv,S<:AbstractMatrix}(A::Symmetric{Tv,S}) = Symmetric{Tv,S}(-A.data, A.uplo)
+
 ## Matvec
 A_mul_B!{T<:BlasFloat,S<:StridedMatrix}(y::StridedVector{T}, A::Symmetric{T,S}, x::StridedVector{T}) = BLAS.symv!(A.uplo, one(T), A.data, x, zero(T), y)
 A_mul_B!{T<:BlasComplex,S<:StridedMatrix}(y::StridedVector{T}, A::Hermitian{T,S}, x::StridedVector{T}) = BLAS.hemv!(A.uplo, one(T), A.data, x, zero(T), y)

diff --git a/test/linalg/symmetric.jl b/test/linalg/symmetric.jl
@@ -209,3 +209,9 @@ let A = [1.0+im 2.0; 2.0 0.0]
  @test !ishermitian(A)
  @test_throws ArgumentError Hermitian(A)
 end
+
+# Unary minus for Symmetric matrices
+let A = Symmetric(randn(5,5))
+ B = -A
+ @test A + B ≈ zeros(5,5)
+end