Refactor expectation_value implementations

src/PEPSKit.jl

@@ -52,6 +52,8 @@ using DocStringExtensions
 include("Defaults.jl")  # Include first to allow for docstring interpolation with Defaults values
 
 include("utility/util.jl")
+include("utility/contraction_labels.jl")
+include("utility/tensor_traces.jl")
 include("utility/indexing.jl")
 include("utility/diffable_threads.jl")
 include("utility/twistdual.jl")
@@ -95,15 +97,21 @@ include("algorithms/contractions/ctmrg/halfinf_env.jl")
 include("algorithms/contractions/ctmrg/fullinf_env.jl")
 include("algorithms/contractions/ctmrg/renormalize_corner.jl")
 include("algorithms/contractions/ctmrg/renormalize_edge.jl")
-include("algorithms/contractions/ctmrg/contract_site.jl")
+include("algorithms/contractions/ctmrg/network_value.jl")
 include("algorithms/contractions/ctmrg/gaugefix.jl")
 include("algorithms/contractions/ctmrg/characteristic_equations.jl")
 
+include("algorithms/contractions/absorb.jl")
 include("algorithms/contractions/absorb_weight.jl")
 include("algorithms/contractions/transfer.jl")
-include("algorithms/contractions/localoperator.jl")
 include("algorithms/contractions/vumps_contractions.jl")
-include("algorithms/contractions/bp_contractions.jl")
+include("algorithms/contractions/bp_messages.jl")
+include("algorithms/contractions/local_patch/expr_utils.jl")
+include("algorithms/contractions/local_patch/network_expr.jl")
+include("algorithms/contractions/local_patch/patch_contractions.jl")
+include("algorithms/contractions/local_patch/densitymatrix/generic.jl")
+include("algorithms/contractions/local_patch/densitymatrix/ctmrg.jl")
+include("algorithms/contractions/local_patch/densitymatrix/bp.jl")
 include("algorithms/contractions/bondenv/benv_tools.jl")
 include("algorithms/contractions/bondenv/gaugefix.jl")
 include("algorithms/contractions/bondenv/als_solve.jl")
@@ -145,9 +153,13 @@ include("algorithms/bp/beliefpropagation.jl")
 include("algorithms/bp/gaugefix.jl")
 
 include("algorithms/transfermatrix.jl")
+include("algorithms/expectation_value/expectation_value.jl")
+include("algorithms/expectation_value/reduced_densitymatrix.jl")
+include("algorithms/expectation_value/patch_contractions.jl")
+include("algorithms/expectation_value/network_value.jl")
+include("algorithms/expectation_value/correlator_adapters.jl")
+include("algorithms/expectation_value/correlators.jl")
 include("algorithms/toolbox.jl")
-include("algorithms/correlator_adapters.jl")
-include("algorithms/correlators.jl")
 
 include("algorithms/optimization/implicit_differentiation.jl")
 include("algorithms/optimization/preconditioning.jl")

src/algorithms/contractions/absorb.jl

@@ -0,0 +1,62 @@
+# Absorption of matrices into tensor legs
+# ---------------------------------------
+
+"""
+    absorb_left(
+        A::AbstractTensorMap{<:Any, S}, C::AbstractTensorMap{<:Any, S, 1, 1}
+    ) where {S}
+
+Absorb a matrix `C` into the left of a tensor map `A` by contracting the first index of `A` with the last index of `C`.
+"""
+function absorb_left(
+        A::AbstractTensorMap{<:Any, S}, C::AbstractTensorMap{<:Any, S, 1, 1}
+    ) where {S}
+    pC = (codomainind(C), domainind(C))
+    pA = ((codomainind(A)[1],), (codomainind(A)[2:end]..., domainind(A)...))
+    pCA = (codomainind(A), domainind(A))
+    return tensorcontract(C, pC, false, A, pA, false, pCA)
+end
+function absorb_left(
+        P::AbstractTensorMap{<:Any, S, 1, N}, C::AbstractTensorMap{<:Any, S, 1, 1}
+    ) where {S, N}
+    return twistnondual(C, 2) * P
+end
+
+"""
+    absorb_right(
+        A::AbstractTensorMap{<:Any, S}, C::AbstractTensorMap{<:Any, S, 1, 1}
+    ) where {S}
+
+Absorb a matrix `C` into the right of a tensor map `A` by contracting the first index in the domain of `A` with the first index of `C`.
+In the case where `A` has only one space in its domain, this can be interpreted as contracting the last leg of `A` with the first leg of `C`.
+"""
+function absorb_right(
+        A::AbstractTensorMap{<:Any, S}, C::AbstractTensorMap{<:Any, S, 1, 1}
+    ) where {S}
+    pA = ((codomainind(A)..., domainind(A)[2:end]...), (domainind(A)[1],))
+    pC = (codomainind(C), domainind(C))
+    pAC = (codomainind(A), (domainind(A)[end], domainind(A)[1:(end - 1)]...))
+    return tensorcontract(A, pA, false, C, pC, false, pAC)
+end
+function absorb_right(
+        E::AbstractTensorMap{<:Any, S, N, 1}, C::AbstractTensorMap{<:Any, S, 1, 1}
+    ) where {S, N}
+    return E * twistdual(C, 1)
+end
+
+"""
+    absorb_left_right(
+        A::AbstractTensorMap{<:Any, S},
+        CL::AbstractTensorMap{<:Any, S, 1, 1},
+        CR::AbstractTensorMap{<:Any, S, 1, 1}
+    ) where {S}
+
+Absorb matrices `CL` and `CR` into the left and right of a tensor map `A` by contracting the first leg of `A` with the second leg of `CL` and the first domain index of `A` with the first leg of `CR`.
+"""
+function absorb_left_right(
+        A::AbstractTensorMap{<:Any, S},
+        CL::AbstractTensorMap{<:Any, S, 1, 1},
+        CR::AbstractTensorMap{<:Any, S, 1, 1}
+    ) where {S}
+    return absorb_right(absorb_left(A, CL), CR)
+end