update inv and tests

Author: cscherrer

src/combinators/affine.jl

@@ -10,6 +10,9 @@ Base.propertynames(d::AffineTransform{N}) where {N} = N
 
 @inline Base.inv(f::AffineTransform{(:μ,:σ)}) = AffineTransform((μ = -(f.σ \ f.μ), ω = f.σ))
 @inline Base.inv(f::AffineTransform{(:μ,:ω)}) = AffineTransform((μ = - f.ω * f.μ, σ = f.ω))
+@inline Base.inv(f::AffineTransform{(:σ,)}) = AffineTransform((ω = f.σ,))
+@inline Base.inv(f::AffineTransform{(:ω,)}) = AffineTransform((σ = f.ω,))
+@inline Base.inv(f::AffineTransform{(:μ,)}) = AffineTransform((μ = -f.μ,))
 
 (f::AffineTransform{(:μ,)})(x) = x + f.μ
 (f::AffineTransform{(:σ,)})(x) = f.σ * x

test/runtests.jl

@@ -111,12 +111,17 @@ end
 
 @testset "Affine" begin
     unif = ∫(x -> 0<x<1, Lebesgue(ℝ))
-    f = AffineTransform((μ=3,σ=2))
-    g = AffineTransform((μ=3,ω=2))
-
-    @test Affine((μ=3,σ=2))(unif) == Affine(f, unif)
-    @test Affine((μ=3,ω=2))(unif) == Affine(g, unif)
-    @test density(Affine(f, Affine(inv(f), unif)), 0.5) == 1
+    f1 = AffineTransform((μ=3.,σ=2.))
+    f2 = AffineTransform((μ=3.,ω=2.))
+    f3 = AffineTransform((μ=3.,))
+    f4 = AffineTransform((σ=2.,))
+    f5 = AffineTransform((ω=2.,))
+
+    for f in [f1,f2,f3,f4,f5]
+        par = getfield(f, :par)
+        @test Affine(par)(unif) == Affine(f, unif)
+        @test density(Affine(f, Affine(inv(f), unif)), 0.5) == 1
+    end
 end
 
 # @testset "For" begin