remove _project_hermitian

Author: lkdvos

test/chainrules/factorizations.jl

@@ -130,7 +130,7 @@ for V in spacelist
                     remove_eighgauge_dependence!(Δv, d, v)
 
                     # necessary for FiniteDifferences to not complain
-                    eigh_full′ = eigh_full ∘ _project_hermitian
+                    eigh_full′ = eigh_full ∘ project_hermitian
 
                     test_ad_rrule(eigh_full′, t; output_tangent = (Δd, Δv), atol, rtol)
                     test_ad_rrule(first ∘ eigh_full′, t; output_tangent = Δd, atol, rtol)

test/setup.jl

@@ -10,7 +10,7 @@ export Vtr, Vℤ₂, Vfℤ₂, Vℤ₃, VU₁, VfU₁, VCU₁, VSU₂, VfSU₂,
 export default_spacelist, factorization_spacelist, ad_spacelist
 export remove_qrgauge_dependence!, remove_lqgauge_dependence!
 export remove_eiggauge_dependence!, remove_eighgauge_dependence!, remove_svdgauge_dependence!
-export test_ad_rrule, _project_hermitian
+export test_ad_rrule
 export _isunitary, _isone
 
 using Random
@@ -410,7 +410,4 @@ function test_ad_rrule(f, args...; check_inferred = false, kwargs...)
     return nothing
 end
 
-# project_hermitian is non-differentiable for now
-_project_hermitian(x) = (x + x') / 2
-
 end