Network solvers redesign

Project.toml

@@ -1,12 +1,13 @@
 name = "ITensorNetworks"
 uuid = "2919e153-833c-4bdc-8836-1ea460a35fc7"
 authors = ["Matthew Fishman <[email protected]>, Joseph Tindall <[email protected]> and contributors"]
-version = "0.13.12"
+version = "0.14.0"
 
 [deps]
 AbstractTrees = "1520ce14-60c1-5f80-bbc7-55ef81b5835c"
 Combinatorics = "861a8166-3701-5b0c-9a16-15d98fcdc6aa"
 Compat = "34da2185-b29b-5c13-b0c7-acf172513d20"
+ConstructionBase = "187b0558-2788-49d3-abe0-74a17ed4e7c9"
 DataGraphs = "b5a273c3-7e6c-41f6-98bd-8d7f1525a36a"
 DataStructures = "864edb3b-99cc-5e75-8d2d-829cb0a9cfe8"
 Dictionaries = "85a47980-9c8c-11e8-2b9f-f7ca1fa99fb4"
@@ -53,6 +54,7 @@ AbstractTrees = "0.4.4"
 Adapt = "4"
 Combinatorics = "1"
 Compat = "3, 4"
+ConstructionBase = "1.6.0"
 DataGraphs = "0.2.3"
 DataStructures = "0.18"
 Dictionaries = "0.4"

src/ITensorNetworks.jl

@@ -34,11 +34,7 @@ include("formnetworks/quadraticformnetwork.jl")
 include("gauging.jl")
 include("utils.jl")
 include("update_observer.jl")
-include("solvers/local_solvers/eigsolve.jl")
-include("solvers/local_solvers/exponentiate.jl")
-include("solvers/local_solvers/dmrg_x.jl")
-include("solvers/local_solvers/contract.jl")
-include("solvers/local_solvers/linsolve.jl")
+
 include("treetensornetworks/abstracttreetensornetwork.jl")
 include("treetensornetworks/treetensornetwork.jl")
 include("treetensornetworks/opsum_to_ttn/matelem.jl")
@@ -48,18 +44,28 @@ include("treetensornetworks/projttns/abstractprojttn.jl")
 include("treetensornetworks/projttns/projttn.jl")
 include("treetensornetworks/projttns/projttnsum.jl")
 include("treetensornetworks/projttns/projouterprodttn.jl")
-include("solvers/solver_utils.jl")
-include("solvers/defaults.jl")
-include("solvers/insert/insert.jl")
-include("solvers/extract/extract.jl")
-include("solvers/alternating_update/alternating_update.jl")
-include("solvers/alternating_update/region_update.jl")
-include("solvers/tdvp.jl")
-include("solvers/dmrg.jl")
-include("solvers/dmrg_x.jl")
-include("solvers/contract.jl")
-include("solvers/linsolve.jl")
-include("solvers/sweep_plans/sweep_plans.jl")
+
+include("solvers/local_solvers/eigsolve.jl")
+include("solvers/local_solvers/exponentiate.jl")
+include("solvers/local_solvers/runge_kutta.jl")
+include("solvers/truncation_parameters.jl")
+include("solvers/iterators.jl")
+include("solvers/adapters.jl")
+include("solvers/sweep_solve.jl")
+include("solvers/region_plans/dfs_plans.jl")
+include("solvers/region_plans/euler_tour.jl")
+include("solvers/region_plans/euler_plans.jl")
+include("solvers/region_plans/tdvp_region_plans.jl")
+include("solvers/extracter.jl")
+include("solvers/inserter.jl")
+include("solvers/subspace/subspace.jl")
+include("solvers/subspace/densitymatrix.jl")
+include("solvers/align_indices.jl")
+include("solvers/operator_map.jl")
+include("solvers/eigsolve.jl")
+include("solvers/applyexp.jl")
+include("solvers/fitting.jl")
+
 include("apply.jl")
 include("inner.jl")
 include("normalize.jl")

src/apply.jl

@@ -186,7 +186,7 @@ function simple_update_bp(o, ψ, v⃗; envs, callback=Returns(nothing), apply_kw
 end
 
 function ITensors.apply(
-  o,
+  o::Union{ITensor,NamedEdge},
   ψ::AbstractITensorNetwork;
   envs=ITensor[],
   normalize=false,

src/solvers/adapters.jl

@@ -0,0 +1,32 @@
+
+#
+# TupleRegionIterator
+#
+# Adapts outputs to be (region, region_kwargs) tuples
+#
+# More generic design? maybe just assuming RegionIterator
+# or its outputs implement some interface function that
+# generates each tuple?
+#
+
+mutable struct TupleRegionIterator{RegionIter}
+  region_iterator::RegionIter
+end
+
+region_iterator(T::TupleRegionIterator) = T.region_iterator
+
+function Base.iterate(T::TupleRegionIterator, which=1)
+  state = iterate(region_iterator(T), which)
+  isnothing(state) && return nothing
+  (current_region, region_kwargs) = current_region_plan(region_iterator(T))
+  return (current_region, region_kwargs), last(state)
+end
+
+"""
+  region_tuples(R::RegionIterator)
+
+The `region_tuples` adapter converts a RegionIterator into an 
+iterator which outputs a tuple of the form (current_region, current_region_kwargs)
+at each step.
+"""
+region_tuples(R::RegionIterator) = TupleRegionIterator(R)

src/solvers/align_indices.jl

@@ -0,0 +1,16 @@
+
+function align_indices(tn)
+  si = siteinds(tn)
+  ptn = copy(tn)
+  for v in vertices(tn)
+    is = inds(tn[v])
+    ls = setdiff(is, si[v])
+    isempty(ls) && continue
+    new_is = [first(ls), si[v]...]
+    if length(ls) >= 2
+      new_is = vcat(new_is, ls[2:end])
+    end
+    ptn[v] = permute(tn[v], new_is)
+  end
+  return ptn
+end