Even more eigfact fun (#294)

* Even more eigfact fun

Author: kshyatt

src/eigen.jl

@@ -6,12 +6,14 @@ end
 @inline function eigvals(a::StaticArray; permute::Bool=true, scale::Bool=true)
     if ishermitian(a)
         _eigvals(Size(a), Hermitian(a), permute, scale)
+    elseif Size(a) == Size{(1,1)}()
+        _eigvals(Size(a), a, permute, scale)
     else
         error("Only hermitian matrices are diagonalizable by *StaticArrays*. Non-Hermitian matrices should be converted to `Array` first.")
     end
 end
 
-@inline _eigvals(::Size{(1,1)}, a, permute, scale) = @inbounds return SVector(real(a.data[1]))
+@inline _eigvals(::Size{(1,1)}, a, permute, scale) = @inbounds return SVector(Tuple(a))
 @inline _eigvals(::Size{(1, 1)}, a::Base.LinAlg.RealHermSymComplexHerm{T}, permute, scale) where {T <: Real} = @inbounds return SVector(real(parent(a).data[1]))
 
 @inline function _eigvals(::Size{(2,2)}, A::Base.LinAlg.RealHermSymComplexHerm{T}, permute, scale) where {T <: Real}

test/eigen.jl

@@ -15,6 +15,9 @@
         ef = eigfact(Symmetric(m))
         @test ef[:values] === SVector(2.0)
         @test ef[:vectors] === SMatrix{1,1}(1.0)
+        # handle non-Hermitian case
+        m = @SMatrix [2.0+im]
+        @test eigvals(m) === SVector(2.0+im)
     end
 
     @testset "2×2" for i = 1:100
@@ -39,6 +42,9 @@
         ef = eigfact(Symmetric(m))
         @test ef[:values]::SVector ≈ vals_a
         @test (ef[:vectors]*diagm(vals)*ef[:vectors]')::SMatrix ≈ m
+        ef = eigfact(Symmetric(m, :L))
+        @test ef[:values]::SVector ≈ vals_a
+        @test (ef[:vectors]*diagm(vals)*ef[:vectors]')::SMatrix ≈ m
 
         (vals, vecs) = eig(Hermitian(m))
         @test vals::SVector ≈ vals_a
@@ -48,6 +54,9 @@
         ef = eigfact(Hermitian(m))
         @test ef[:values]::SVector ≈ vals_a
         @test (ef[:vectors]*diagm(vals)*ef[:vectors]')::SMatrix ≈ m
+        ef = eigfact(Hermitian(m, :L))
+        @test ef[:values]::SVector ≈ vals_a
+        @test (ef[:vectors]*diagm(vals)*ef[:vectors]')::SMatrix ≈ m
 
         m_d = randn(SVector{2}); m = diagm(m_d)
         (vals, vecs) = eig(Hermitian(m))