implement inv() for UniformScaling

skariel · Dec 13, 2014 · 425dbf7 · 425dbf7
1 parent 3234254
commit 425dbf7
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Showing 2 changed files with 5 additions and 1 deletion.
diff --git a/base/linalg/uniformscaling.jl b/base/linalg/uniformscaling.jl
@@ -1,4 +1,4 @@
-import Base: copy, ctranspose, getindex, showarray, transpose, one, zero
+import Base: copy, ctranspose, getindex, showarray, transpose, one, zero, inv
 import Base.LinAlg: SingularException
 
 immutable UniformScaling{T<:Number}
@@ -64,6 +64,8 @@ function -{TA,TJ<:Number}(J::UniformScaling{TJ}, A::AbstractMatrix{TA})
     B
 end
 
+inv(J::UniformScaling) = UniformScaling(inv(J.λ))
+
 *(J1::UniformScaling, J2::UniformScaling) = UniformScaling(J1.λ*J2.λ)
 *(B::BitArray{2}, J::UniformScaling) = *(bitunpack(B), J::UniformScaling)
 *(J::UniformScaling, B::BitArray{2}) = *(J::UniformScaling, bitunpack(B))

diff --git a/test/linalg2.jl b/test/linalg2.jl
@@ -395,6 +395,8 @@ end
 J = UniformScaling(λ)
 @test J*eye(2) == conj(J'eye(2)) # ctranpose (and A(c)_mul_B)
 @test I + I === UniformScaling(2) # +
+@test inv(I) == I
+@test inv(J) == UniformScaling(inv(λ))
 B = randbool(2,2)
 @test B + I == B + eye(B)
 @test I + B == B + eye(B)