Merge pull request #113 from invenia/mz/subtraction

implement faster subtraction
JuliaArrays · Jul 28, 2022 · 932b020 · 932b020 · mzgubic · Jul 28, 2022
2 parents 6223d3f + e754c0f
commit 932b020
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Showing 3 changed files with 5 additions and 1 deletion.
diff --git a/Project.toml b/Project.toml
@@ -1,7 +1,7 @@
 name = "BlockDiagonals"
 uuid = "0a1fb500-61f7-11e9-3c65-f5ef3456f9f0"
 authors = ["Invenia Technical Computing Corporation"]
-version = "0.1.35"
+version = "0.1.36"
 
 [deps]
 ChainRulesCore = "d360d2e6-b24c-11e9-a2a3-2a2ae2dbcce4"

diff --git a/src/base_maths.jl b/src/base_maths.jl
@@ -66,6 +66,8 @@ end
 ## Subtraction
 Base.:-(B::BlockDiagonal) = BlockDiagonal(.-(blocks(B)))
 Base.:-(M::AbstractMatrix, B::BlockDiagonal) = M + -B
+Base.:-(B::BlockDiagonal, M::AbstractMatrix) = -M + B
+Base.:-(B::BlockDiagonal, B2::BlockDiagonal) = B + (-B2)
 
 ## Multiplication
 Base.:*(n::Number, B::BlockDiagonal) = B * n

diff --git a/test/base_maths.jl b/test/base_maths.jl
@@ -76,6 +76,8 @@ using Test
 
  @test -b1 == -Matrix(b1)
  @test b1 - b1 == Matrix(b1) - Matrix(b1)
+ @test Matrix(b1) - b2 == Matrix(b1) - Matrix(b2)
+ @test b1 - Matrix(b2) == Matrix(b1) - Matrix(b2)
  end
 
  @testset "Multiplication" begin