Preserve message type upon use of rescale (#254)

Author: JoeyT1994

Project.toml

@@ -1,7 +1,7 @@
 name = "ITensorNetworks"
 uuid = "2919e153-833c-4bdc-8836-1ea460a35fc7"
 authors = ["Matthew Fishman <[email protected]>, Joseph Tindall <[email protected]> and contributors"]
-version = "0.14.0"
+version = "0.14.1"
 
 [deps]
 AbstractTrees = "1520ce14-60c1-5f80-bbc7-55ef81b5835c"

src/caches/abstractbeliefpropagationcache.jl

@@ -382,8 +382,8 @@ function rescale_partitions(
     isempty(pv_vs) && continue
 
     vn = region_scalar(bpc, pv)
-    s = isreal(vn) ? sign(vn) : 1.0
-    vn = s * inv(vn^(1 / length(pv_vs)))
+    s = isreal(vn) ? sign(vn) : one(vn)
+    vn = s * vn^(-inv(oftype(vn, length(pv_vs))))
     set!(vertices_weights, first(pv_vs), s*vn)
     for v in pv_vs[2:length(pv_vs)]
       set!(vertices_weights, v, vn)

src/caches/beliefpropagationcache.jl

@@ -141,7 +141,7 @@ function rescale_messages(bp_cache::BeliefPropagationCache, pes::Vector{<:Partit
       n *= sign(n)
     end
 
-    sf = (1 / sqrt(n)) ^ (1 / length(me))
+    sf = inv(sqrt(n)) ^ inv(oftype(n, length(me)))
     set!(mts, pe, sf .* me)
     set!(mts, reverse(pe), sf .* mer)
   end

test/Project.toml

@@ -44,7 +44,7 @@ Glob = "1.3.1"
 Graphs = "1.12.0"
 GraphsFlows = "0.1.1"
 ITensorMPS = "0.3.6"
-ITensorNetworks = "0.14.0"
+ITensorNetworks = "0.14.1"
 ITensors = "0.7, 0.8, 0.9"
 KrylovKit = "0.8, 0.9, 0.10"
 LinearAlgebra = "1.10.0"

test/test_normalize.jl

@@ -4,7 +4,9 @@ using ITensorNetworks:
   QuadraticFormNetwork,
   edge_scalars,
   norm_sqr_network,
+  messages,
   random_tensornetwork,
+  scalartype,
   siteinds,
   vertex_scalars,
   rescale
@@ -39,7 +41,7 @@ using Test: @test, @testset
 
   g = named_grid((Lx, Ly))
   s = siteinds("S=1/2", g)
-  x = random_tensornetwork(rng, s; link_space=χ)
+  x = random_tensornetwork(rng, ComplexF32, s; link_space=χ)
 
   ψ = normalize(x; alg="exact")
   @test scalar(norm_sqr_network(ψ); alg="exact") ≈ 1.0
@@ -49,6 +51,7 @@ using Test: @test, @testset
     x; alg="bp", (cache!)=ψIψ_bpc, update_cache=true, cache_update_kwargs=(; maxiter=20)
   )
   ψIψ_bpc = ψIψ_bpc[]
+  @test all(m -> scalartype(only(m)) == ComplexF32, messages(ψIψ_bpc))
   @test all(x -> x ≈ 1.0, edge_scalars(ψIψ_bpc))
   @test all(x -> x ≈ 1.0, vertex_scalars(ψIψ_bpc))
   @test scalar(QuadraticFormNetwork(ψ); alg="bp", cache_update_kwargs=(; maxiter=20)) ≈ 1.0