Forward negation of a Tridiagonal matrix to diagonals (#43942)

JuliaLang · Jan 27, 2022 · 4650cff · 4650cff
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commit 4650cff
Showing 1 changed file with 1 addition and 0 deletions.
diff --git a/stdlib/LinearAlgebra/src/tridiag.jl b/stdlib/LinearAlgebra/src/tridiag.jl
@@ -736,6 +736,7 @@ end
 
 +(A::Tridiagonal, B::Tridiagonal) = Tridiagonal(A.dl+B.dl, A.d+B.d, A.du+B.du)
 -(A::Tridiagonal, B::Tridiagonal) = Tridiagonal(A.dl-B.dl, A.d-B.d, A.du-B.du)
+-(A::Tridiagonal) = Tridiagonal(-A.dl, -A.d, -A.du)
 *(A::Tridiagonal, B::Number) = Tridiagonal(A.dl*B, A.d*B, A.du*B)
 *(B::Number, A::Tridiagonal) = Tridiagonal(B*A.dl, B*A.d, B*A.du)
 /(A::Tridiagonal, B::Number) = Tridiagonal(A.dl/B, A.d/B, A.du/B)