eig and svd vals

Author: mtfishman

src/KroneckerArrays.jl

@@ -579,7 +579,9 @@ end
 using MatrixAlgebraKit:
   copy_input,
   eig_full,
+  eig_vals,
   eigh_full,
+  eigh_vals,
   qr_compact,
   qr_full,
   left_orth,
@@ -741,7 +743,9 @@ _copy_input_squareeye(f::F, a::SquareEye) where {F} = a
 
 for f in [
   :eig_full,
+  :eig_vals,
   :eigh_full,
+  :eigh_vals,
   :qr_compact,
   :qr_full,
   :left_orth,
@@ -857,4 +861,36 @@ for f in [
   end
 end
 
+for f in [:eig_vals!, :eigh_vals!, :svd_vals!]
+  @eval begin
+    _initialize_output_squareeye(::typeof($f), a::SquareEye) = parent(a)
+    _initialize_output_squareeye(::typeof($f), a::SquareEye, alg) = parent(a)
+  end
+end
+
+for f in [:eig_vals!, :eigh_vals!, :svd_vals!]
+  f′ = Symbol("_", f, "_squareeye")
+  @eval begin
+    $f′(a, F, alg; kwargs...) = $f(a, F, alg; kwargs...)
+    $f′(a, F, alg::SquareEyeAlgorithm) = F
+  end
+  for T in [:SquareEyeKronecker, :KroneckerSquareEye, :SquareEyeSquareEye]
+    @eval begin
+      function MatrixAlgebraKit.initialize_output(
+        ::typeof($f), a::$T, alg::KroneckerAlgorithm
+      )
+        return _initialize_output_squareeye($f, a.a, alg.a) ⊗
+               _initialize_output_squareeye($f, a.b, alg.b)
+      end
+      function MatrixAlgebraKit.$f(
+        a::$T, F, alg::KroneckerAlgorithm; kwargs1=(;), kwargs2=(;), kwargs...
+      )
+        $f′(a.a, F.a, alg.a; kwargs..., kwargs1...)
+        $f′(a.b, F.b, alg.b; kwargs..., kwargs2...)
+        return F
+      end
+    end
+  end
+end
+
 end

test/test_matrixalgebrakit.jl

@@ -1,4 +1,4 @@
-using FillArrays: Eye
+using FillArrays: Eye, Ones
 using KroneckerArrays: ⊗, arguments
 using LinearAlgebra: Hermitian, I, diag, hermitianpart, norm
 using MatrixAlgebraKit:
@@ -154,6 +154,28 @@ end
     @test arguments(v, 2) isa Eye
   end
 
+  for f in (eig_vals, eigh_vals)
+    a = Eye(3) ⊗ parent(hermitianpart(randn(3, 3)))
+    d = @constinferred f(a)
+    d′ = f(Matrix(a))
+    @test sort(Vector(d); by=abs) ≈ sort(d′; by=abs)
+    @test arguments(d, 1) isa Ones
+    @test arguments(d, 2) ≈ f(arguments(a, 2))
+
+    a = parent(hermitianpart(randn(3, 3))) ⊗ Eye(3)
+    d = @constinferred f(a)
+    d′ = f(Matrix(a))
+    @test sort(Vector(d); by=abs) ≈ sort(d′; by=abs)
+    @test arguments(d, 2) isa Ones
+    @test arguments(d, 1) ≈ f(arguments(a, 1))
+
+    a = Eye(3) ⊗ Eye(3)
+    d = @constinferred f(a)
+    @test d == Ones(3) ⊗ Ones(3)
+    @test arguments(d, 1) isa Ones
+    @test arguments(d, 2) isa Ones
+  end
+
   for f in (
     left_orth, left_polar, lq_compact, lq_full, qr_compact, qr_full, right_orth, right_polar
   )
@@ -203,4 +225,24 @@ end
     @test arguments(s, 2) isa Eye
     @test arguments(v, 2) isa Eye
   end
+
+  a = Eye(3) ⊗ randn(3, 3)
+  d = @constinferred svd_vals(a)
+  d′ = svd_vals(Matrix(a))
+  @test sort(Vector(d); by=abs) ≈ sort(d′; by=abs)
+  @test arguments(d, 1) isa Ones
+  @test arguments(d, 2) ≈ svd_vals(arguments(a, 2))
+
+  a = randn(3, 3) ⊗ Eye(3)
+  d = @constinferred svd_vals(a)
+  d′ = svd_vals(Matrix(a))
+  @test sort(Vector(d); by=abs) ≈ sort(d′; by=abs)
+  @test arguments(d, 2) isa Ones
+  @test arguments(d, 1) ≈ svd_vals(arguments(a, 1))
+
+  a = Eye(3) ⊗ Eye(3)
+  d = @constinferred svd_vals(a)
+  @test d == Ones(3) ⊗ Ones(3)
+  @test arguments(d, 1) isa Ones
+  @test arguments(d, 2) isa Ones
 end