Use internal ITensorNetworks code for sequence finding

Author: JoeyT1994

src/caches/abstractbeliefpropagationcache.jl

@@ -17,7 +17,8 @@ using NDTensors: NDTensors
 abstract type AbstractBeliefPropagationCache end
 
 function default_message_update(contract_list::Vector{ITensor}; normalize=true, kwargs...)
-  updated_messages = contract(contract_list; sequence="automatic", kwargs...)
+  sequence = contraction_sequence(contract_list; alg="optimal")
+  updated_messages = contract(contract_list; sequence, kwargs...)
   message_norm = norm(updated_messages)
   if normalize && !iszero(message_norm)
     updated_messages /= message_norm

src/caches/beliefpropagationcache.jl

@@ -94,22 +94,20 @@ function environment(bpc::BeliefPropagationCache, verts::Vector; kwargs...)
   return vcat(messages, central_tensors)
 end
 
-function region_scalar(
-  bp_cache::BeliefPropagationCache,
-  pv::PartitionVertex;
-  contract_kwargs=(; sequence="automatic"),
-)
+function region_scalar(bp_cache::BeliefPropagationCache, pv::PartitionVertex;)
   incoming_mts = incoming_messages(bp_cache, [pv])
   local_state = factors(bp_cache, pv)
-  return contract(vcat(incoming_mts, local_state); contract_kwargs...)[]
+  ts = vcat(incoming_mts, local_state)
+  sequence = contraction_sequence(ts; alg="optimal")
+  return contract(ts; sequence)[]
 end
 
 function region_scalar(
   bp_cache::BeliefPropagationCache,
   pe::PartitionEdge;
   contract_kwargs=(; sequence="automatic"),
 )
-  return contract(
-    vcat(message(bp_cache, pe), message(bp_cache, reverse(pe))); contract_kwargs...
-  )[]
+  ts = vcat(message(bp_cache, pe), message(bp_cache, reverse(pe)))
+  sequence = contraction_sequence(ts; alg="optimal")
+  return contract(ts; sequence)[]
 end

src/expect.jl

@@ -4,16 +4,18 @@ using ITensorMPS: ITensorMPS, expect
 
 default_expect_alg() = "bp"
 
-function ITensorMPS.expect(
-  ψIψ::AbstractFormNetwork, op::Op; contract_kwargs=(; sequence="automatic"), kwargs...
-)
+function ITensorMPS.expect(ψIψ::AbstractFormNetwork, op::Op; kwargs...)
   v = only(op.sites)
   ψIψ_v = ψIψ[operator_vertex(ψIψ, v)]
   s = commonind(ψIψ[ket_vertex(ψIψ, v)], ψIψ_v)
   operator = ITensors.op(op.which_op, s)
   ∂ψIψ_∂v = environment(ψIψ, operator_vertices(ψIψ, [v]); kwargs...)
-  numerator = contract(vcat(∂ψIψ_∂v, operator); contract_kwargs...)[]
-  denominator = contract(vcat(∂ψIψ_∂v, ψIψ_v); contract_kwargs...)[]
+  numerator_ts = vcat(∂ψIψ_∂v, operator)
+  denominator_ts = vcat(∂ψIψ_∂v, ψIψ_v)
+  numerator_seq = contraction_sequence(numerator_ts; alg="optimal")
+  denominator_seq = contraction_sequence(denominator_ts; alg="optimal")
+  numerator = contract(numerator_ts; sequence)[]
+  denominator = contract(denominator_ts; sequence)[]
 
   return numerator / denominator
 end