Adapt contract(_updater) to new interface.

src/ITensorNetworks.jl

@@ -109,6 +109,7 @@ include(joinpath("Graphs", "abstractdatagraph.jl"))
 include(joinpath("solvers", "eigsolve.jl"))
 include(joinpath("solvers", "exponentiate.jl"))
 include(joinpath("solvers", "dmrg_x.jl"))
+include(joinpath("solvers", "contract.jl"))
 include(joinpath("treetensornetworks", "abstracttreetensornetwork.jl"))
 include(joinpath("treetensornetworks", "ttn.jl"))
 include(joinpath("treetensornetworks", "opsum_to_ttn.jl"))

src/solvers/contract.jl

@@ -0,0 +1,19 @@
+function contract_updater(
+    init;
+    state!,
+    projected_operator!,
+    outputlevel,
+    which_sweep,
+    sweep_plan,
+    which_region_update,
+    region_kwargs,
+    updater_kwargs,
+    )
+    v = ITensor(1.0)
+    projected_operator = projected_operator![]
+    for j in sites(projected_operator)
+      v *= projected_operator.psi0[j]
+    end
+    Hpsi0 = contract(projected_operator, v)
+    return Hpsi0, (;)
+  end

src/treetensornetworks/solvers/contract.jl

@@ -1,18 +1,11 @@
-function contract_solver(PH, psi; normalize, region, half_sweep)
-  v = ITensor(1.0)
-  for j in sites(PH)
-    v *= PH.psi0[j]
-  end
-  Hpsi0 = contract(PH, v)
-  return Hpsi0, NamedTuple()
-end
-
 function contract(
   ::Algorithm"fit",
   tn1::AbstractTTN,
   tn2::AbstractTTN;
   init=random_ttn(flatten_external_indsnetwork(tn1, tn2); link_space=trivial_space(tn1)),
   nsweeps=1,
+  nsites=2, # used to be default of call to default_sweep_regions
+  updater_kwargs=(;),
   kwargs...,
 )
   n = nv(tn1)
@@ -42,7 +35,8 @@ function contract(
   ## end
 
   PH = ProjTTNApply(tn2, tn1)
-  psi = alternating_update(contract_solver, PH, init; nsweeps, kwargs...)
+  sweep_plan = default_sweep_regions(nsites, init; kwargs...)
+  psi = alternating_update(contract_updater, PH, init; nsweeps, sweep_plan, updater_kwargs, kwargs...)
 
   return psi
 end

test/test_treetensornetworks/test_solvers/test_contract.jl

@@ -46,7 +46,7 @@ using Test
 
   # Test with nsite=1
   Hpsi_guess = random_mps(t; internal_inds_space=32)
-  Hpsi = apply(H, psi; alg="fit", init=Hpsi_guess, nsite=1, nsweeps=4)
+  Hpsi = apply(H, psi; alg="fit", init=Hpsi_guess, nsites=1, nsweeps=4)
   @test inner(psit, Hpsi) ≈ inner(psit, H, psi) atol = 1E-4
 end
 
@@ -84,7 +84,7 @@ end
 
   # Test with nsite=1
   Hpsi_guess = random_ttn(t; link_space=4)
-  Hpsi = apply(H, psi; alg="fit", nsite=1, nsweeps=4, init=Hpsi_guess)
+  Hpsi = apply(H, psi; alg="fit", nsites=1, nsweeps=4, init=Hpsi_guess)
   @test inner(psit, Hpsi) ≈ inner(psit, H, psi) atol = 1E-4
 end