From 4adb8379bb3a11706e35a03ac596b76a0ace3000 Mon Sep 17 00:00:00 2001
From: GianlucaFuwa <gianlucafuwa@gmail.com>
Date: Fri, 7 Jun 2024 21:27:54 +0200
Subject: [PATCH] Enable eigenvalue measurement for even-odd staggered
 (DdaggerD only)

---
 src/diracoperators/DiracOperators.jl    | 16 ++++++++++++++--
 src/gaugefields/fermionfields.jl        | 13 ++++++++++++-
 src/measurements/measure_eigenvalues.jl |  2 ++
 3 files changed, 28 insertions(+), 3 deletions(-)

diff --git a/src/diracoperators/DiracOperators.jl b/src/diracoperators/DiracOperators.jl
index 3c5e1592..3e26a755 100644
--- a/src/diracoperators/DiracOperators.jl
+++ b/src/diracoperators/DiracOperators.jl
@@ -133,25 +133,37 @@ end
 
 function construct_diracmatrix(D, U)
     n = checksquare(D)
-    Du = D(U)
+    Du = DdaggerD(D(U))
     M = spzeros(ComplexF64, n, n) 
     temp1 = similar(get_temp(D))
     temp2 = similar(get_temp(D))
     ND = num_dirac(temp1)
+    fdims = dims(U)
+    NV = U.NV
     @assert n < 5000
+    is_evenodd = temp1 isa EvenOdd
    
     ii = 1
     for isite in eachindex(U)
+        if is_evenodd
+            iseven(isite) || continue
+        end
         for α in 1:ND
             for a in 1:3
                 set_source!(temp1, isite, a, α)
                 mul!(temp2, Du, temp1)
                 jj = 1
                 for jsite in eachindex(U)
+                    if is_evenodd
+                        iseven(jsite) || continue
+                        _jsite = eo_site(jsite, fdims..., NV)
+                    else
+                        _jsite = jsite
+                    end
                     for β in 1:ND
                         for b in 1:3
                             ind = (β - 1) * 3 + b
-                            M[jj, ii] = temp2[jsite][ind]
+                            M[jj, ii] = temp2[_jsite][ind]
                             jj += 1
                         end
                     end
diff --git a/src/gaugefields/fermionfields.jl b/src/gaugefields/fermionfields.jl
index f40be32c..9aa02f31 100644
--- a/src/gaugefields/fermionfields.jl
+++ b/src/gaugefields/fermionfields.jl
@@ -171,10 +171,21 @@ end
 Base.size(f::EvenOdd) = size(f.parent)
 Base.similar(f::EvenOdd) = even_odd(Fermionfield(f.parent))
 Base.eltype(::EvenOdd{B,T}) where {B,T} = Complex{T}
-LinearAlgebra.checksquare(f::EvenOdd) = LinearAlgebra.checksquare(f.parent)
+LinearAlgebra.checksquare(f::EvenOdd) = LinearAlgebra.checksquare(f.parent) ÷ 2
 num_colors(::EvenOdd{B,T,A,ND}) where {B,T,A,ND} = 3
 num_dirac(::EvenOdd{B,T,A,ND}) where {B,T,A,ND} = ND
 
+Base.@propagate_inbounds Base.getindex(f::EvenOdd, i::Integer) = f.parent.U[i]
+Base.@propagate_inbounds Base.getindex(f::EvenOdd, x, y, z, t) = f.parent.U[x, y, z, t]
+Base.@propagate_inbounds Base.getindex(f::EvenOdd, site::SiteCoords) = f.parent.U[site]
+Base.@propagate_inbounds Base.setindex!(f::EvenOdd, v, i::Integer) =
+    setindex!(f.parent.U, v, i)
+Base.@propagate_inbounds Base.setindex!(f::EvenOdd, v, x, y, z, t) =
+    setindex!(f.parent.U, v, x, y, z, t)
+Base.@propagate_inbounds Base.setindex!(f::EvenOdd, v, site::SiteCoords) =
+    setindex!(f.parent.U, v, site)
+
+
 clear!(ϕ_eo::EvenOdd) = clear!(ϕ_eo.parent)
 ones!(ϕ_eo::EvenOdd) = ones!(ϕ_eo.parent)
 
diff --git a/src/measurements/measure_eigenvalues.jl b/src/measurements/measure_eigenvalues.jl
index 33dd306f..aeec4d46 100644
--- a/src/measurements/measure_eigenvalues.jl
+++ b/src/measurements/measure_eigenvalues.jl
@@ -34,6 +34,8 @@ struct EigenvaluesMeasurement{T,TA,TD} <: AbstractMeasurement
                 dirac_operator = StaggeredEOPreDiracOperator(
                     U, mass; anti_periodic=anti_periodic
                 )
+                @level1("@Warn Eigenvalues with \"eo_precon=true\" defaults to DdaggerD")
+                ddaggerd = true
             else
                 dirac_operator = StaggeredDiracOperator(
                     U, mass; anti_periodic=anti_periodic