Improved tags for site indices and construction of site indices

examples/2d_laplace_solver.jl

@@ -23,11 +23,11 @@ using UnicodePlots
 seed!(1234)
 L = 14
 g = NamedGraph(SimpleGraph(uniform_tree(L)))
-s = siteinds("S=1/2", g)
 
 vertex_to_dimension_map = Dictionary(vertices(g), [(v[1] % 2) + 1 for v in vertices(g)])
 vertex_to_bit_map = Dictionary(vertices(g), [ceil(Int64, v[1] * 0.5) for v in vertices(g)])
 bit_map = BitMap(vertex_to_bit_map, vertex_to_dimension_map)
+s = siteinds(g, bit_map)
 
 ψ_fxy = 0.1 * rand_itn(s, bit_map; link_space=2)
 ∇ = laplacian_operator(s, bit_map; scale=false)

src/ITensorNumericalAnalysis.jl

@@ -1,10 +1,10 @@
 module ITensorNumericalAnalysis
 
-include("itensornetworksutils.jl")
-include("bitmaps.jl")
+include("bitmap.jl")
+include("utils.jl")
 include("itensornetworkfunction.jl")
-include("itensornetworks_elementary_functions.jl")
-include("itensornetworks_elementary_operators.jl")
+include("elementary_functions.jl")
+include("elementary_operators.jl")
 
 export ITensorNetworkFunction, itensornetwork
 export BitMap,

src/itensornetworks_elementary_operators.jl → src/elementary_operators.jl

@@ -1,33 +1,51 @@
 using Graphs: is_tree
 using NamedGraphs: undirected_graph
 using ITensors:
-  sim,
   OpSum,
+  @OpName_str,
+  @SiteType_str,
+  SiteType,
   siteinds,
   noprime,
+  op,
   truncate,
   replaceinds!,
   delta,
   add!,
   prime,
+  sim,
   noprime!,
   contract
 using ITensorNetworks: IndsNetwork, ITensorNetwork, TreeTensorNetwork, combine_linkinds, ttn
 
+function ITensors.op(::OpName"D+", ::SiteType"Digit", s::Index)
+  d = dim(s)
+  o = zeros(d, d)
+  o[2, 1] = 1
+  return ITensor(o, s, s')
+end
+function ITensors.op(::OpName"D-", ::SiteType"Digit", s::Index)
+  d = dim(s)
+  o = zeros(d, d)
+  o[1, 2] = 1
+  return ITensor(o, s, s')
+end
+
 function plus_shift_ttn(
   s::IndsNetwork, bit_map; dimension=default_dimension(), boundary_value=[0.0]
 )
   @assert is_tree(s)
+  @assert base(bit_map) == 2
   ttn_op = OpSum()
   dim_vertices = vertices(bit_map, dimension)
   L = length(dim_vertices)
 
-  string_site = [("S+", vertex(bit_map, dimension, L))]
-  add!(ttn_op, 1.0, "S+", vertex(bit_map, dimension, L))
+  string_site = [("D+", vertex(bit_map, dimension, L))]
+  add!(ttn_op, 1.0, "D+", vertex(bit_map, dimension, L))
   for i in L:-1:2
     pop!(string_site)
-    push!(string_site, ("S-", vertex(bit_map, dimension, i)))
-    push!(string_site, ("S+", vertex(bit_map, dimension, i - 1)))
+    push!(string_site, ("D-", vertex(bit_map, dimension, i)))
+    push!(string_site, ("D+", vertex(bit_map, dimension, i - 1)))
     add!(ttn_op, 1.0, (string_site...)...)
   end
 
@@ -36,16 +54,17 @@ end
 
 function minus_shift_ttn(s::IndsNetwork, bit_map; dimension=default_dimension())
   @assert is_tree(s)
+  @assert base(bit_map) == 2
   ttn_op = OpSum()
   dim_vertices = vertices(bit_map, dimension)
   L = length(dim_vertices)
 
-  string_site = [("S-", vertex(bit_map, dimension, L))]
-  add!(ttn_op, 1.0, "S-", vertex(bit_map, dimension, L))
+  string_site = [("D-", vertex(bit_map, dimension, L))]
+  add!(ttn_op, 1.0, "D-", vertex(bit_map, dimension, L))
   for i in L:-1:2
     pop!(string_site)
-    push!(string_site, ("S+", vertex(bit_map, dimension, i)))
-    push!(string_site, ("S-", vertex(bit_map, dimension, i - 1)))
+    push!(string_site, ("D+", vertex(bit_map, dimension, i)))
+    push!(string_site, ("D-", vertex(bit_map, dimension, i - 1)))
     add!(ttn_op, 1.0, (string_site...)...)
   end
 

src/itensornetworkfunction.jl

@@ -1,4 +1,4 @@
-using ITensorNetworks: ITensorNetworks, AbstractITensorNetwork, data_graph
+using ITensorNetworks: ITensorNetworks, AbstractITensorNetwork, data_graph, data_graph_type
 using ITensors: ITensor, dim, contract, siteinds, onehot
 using Graphs: Graphs
 

src/itensornetworksutils.jl → src/utils.jl

@@ -1,5 +1,6 @@
-using ITensors: Index, dim, inds
-using ITensorNetworks: random_tensornetwork, IndsNetwork
+using Graphs: AbstractGraph
+using ITensors: ITensors, Index, dim, inds, siteinds
+using ITensorNetworks: random_tensornetwork, IndsNetwork, vertex_tag
 
 """Build the order L tensor corresponding to fx(x): x ∈ [0,1], default decomposition is binary"""
 function build_full_rank_tensor(L::Int64, fx::Function; base::Int64=2)
@@ -29,3 +30,19 @@ function c_tensor(phys_ind::Index, virt_inds::Vector)
 
   return T
 end
+
+"""Tag for a vertex based on its dimension (Dim) and digit (N)"""
+function digit_tag(bm::BitMap, v)
+  dig = digit(bm, v)
+  dim = dimension(bm, v)
+  return "N $dig, Dim $dim"
+end
+
+"""Generate network of physical indices given a graph and a bitmap"""
+function ITensors.siteinds(g::AbstractGraph, bm::BitMap)
+  is = IndsNetwork(g)
+  for v in vertices(g)
+    is[v] = [Index(base(bm), "Digit, $(digit_tag(bm, v)), V$(vertex_tag(v))")]
+  end
+  return is
+end

test/test_bitmaps.jl

@@ -9,9 +9,10 @@ using Dictionaries: Dictionary
   L = 4
 
   g = named_grid((L, L))
-  s = siteinds("S=1/2", g)
   bit_map = BitMap(g)
 
+  s = siteinds(g, bit_map)
+
   @test dimension(bit_map) == 1
   @test Set(vertices(bit_map)) == Set(vertices(g))
   @test base(bit_map) == 2

test/test_itensorfunction.jl

@@ -34,10 +34,10 @@ end
   @testset "test const" begin
     L = 3
     g = named_grid((L, L))
-    s = siteinds("S=1/2", g)
+    bit_map = BitMap(g)
+    s = siteinds(g, bit_map)
     c = 1.5
 
-    bit_map = BitMap(g)
     ψ_fx = const_itn(s, bit_map; c)
 
     x = 0.5
@@ -60,9 +60,9 @@ end
       g = named_comb_tree((2, 3))
       a = 1.2
       k = 0.125
-      s = siteinds("S=1/2", g)
 
       bit_map = BitMap(g)
+      s = siteinds(g, bit_map)
 
       x = 0.625
       ψ_fx = net_func(s, bit_map; k, a)
@@ -85,9 +85,9 @@ end
       a = 1.2
       k = 0.125
       b = 3
-      s = siteinds("S=1", g)
 
       bit_map = BitMap(g; base=b)
+      s = siteinds(g, bit_map)
 
       x = (5.0 / 9.0)
       ψ_fx = net_func(s, bit_map; k, a)
@@ -103,9 +103,9 @@ end
     a = 1.3
     k = 0.15
     nterms = 50
-    s = siteinds("S=1/2", g)
 
     bit_map = BitMap(g)
+    s = siteinds(g, bit_map)
 
     x = 0.625
     ψ_fx = tanh_itn(s, bit_map; k, a, nterms)
@@ -123,11 +123,11 @@ end
       seed!(1234 * deg)
       g = NamedGraph(SimpleGraph(uniform_tree(L)))
       g = rename_vertices(g, Dict(zip(vertices(g), [(v, 1) for v in vertices(g)])))
-      s = siteinds("S=1/2", g)
+      bit_map = BitMap(g)
+      s = siteinds(g, bit_map)
 
       coeffs = [rand(Uniform(-2, 2)) for i in 1:(deg + 1)]
 
-      bit_map = BitMap(g)
       x = 0.875
       ψ_fx = poly_itn(s, bit_map, coeffs)
       fx_x = calculate_fx(ψ_fx, x)
@@ -142,12 +142,13 @@ end
   #Constant function but represented in three dimension
   @testset "test const" begin
     g = named_grid((3, 3))
-    s = siteinds("S=1/2", g)
-    c = 1.5
 
     vertex_to_dimension_map = Dictionary(vertices(g), [v[1] for v in vertices(g)])
     vertex_to_bit_map = Dictionary(vertices(g), [v[2] for v in vertices(g)])
     bit_map = BitMap(vertex_to_bit_map, vertex_to_dimension_map)
+    s = siteinds(g, bit_map)
+
+    c = 1.5
 
     ψ_fxyz = const_itn(s, bit_map; c)
 
@@ -179,7 +180,7 @@ end
     @testset "test $name" begin
       a = 1.2
       k = 0.125
-      s = siteinds("S=1/2", g)
+      s = siteinds(g, bit_map)
 
       ψ_fx = net_func(s, bit_map; k, a, dimension=1)
       ψ_fy = net_func(s, bit_map; k, a, dimension=2)
@@ -197,11 +198,10 @@ end
     a = 1.3
     k = 0.15
     nterms = 10
-    s = siteinds("S=1/2", g)
-
     vertex_to_dimension_map = Dictionary(vertices(g), [v[2] for v in vertices(g)])
     vertex_to_bit_map = Dictionary(vertices(g), [v[1] for v in vertices(g)])
     bit_map = BitMap(vertex_to_bit_map, vertex_to_dimension_map)
+    s = siteinds(g, bit_map)
 
     x, y = 0.625, 0.875
     ψ_fx = tanh_itn(s, bit_map; k, a, nterms, dimension=1)

test/test_operators.jl

@@ -11,8 +11,8 @@ using Dictionaries: Dictionary
 @testset "test laplacian in 1D on MPS" begin
   g = named_grid((12, 1))
   L = nv(g)
-  s = siteinds("S=1/2", g)
   bit_map = BitMap(g)
+  s = siteinds(g, bit_map)
 
   ∇sq = laplacian_operator(s, bit_map; cutoff=1e-10)
   @test maxlinkdim(∇sq) == 3
@@ -30,8 +30,8 @@ end
 @testset "test derivative in 1D on tree" begin
   g = named_comb_tree((4, 4))
   L = nv(g)
-  s = siteinds("S=1/2", g)
   bit_map = BitMap(g)
+  s = siteinds(g, bit_map)
 
   ∂_∂x = derivative_operator(s, bit_map; cutoff=1e-10)
 
@@ -48,8 +48,8 @@ end
 @testset "test multiplication_operator_in_1D" begin
   g = named_comb_tree((4, 4))
   L = nv(g)
-  s = siteinds("S=1/2", g)
   bit_map = BitMap(g)
+  s = siteinds(g, bit_map)
 
   ψ_gx = sin_itn(s, bit_map; k=0.5 * Float64(pi))
   ψ_fx = cos_itn(s, bit_map; k=0.25 * Float64(pi))
@@ -65,7 +65,6 @@ end
 @testset "test multiplication_operator_in_2D" begin
   L = 10
   g = NamedGraph(SimpleGraph(uniform_tree(L)))
-  s = siteinds("S=1/2", g)
 
   vertex_to_dimension_map = Dictionary(
     vertices(g), [(first(v) % 2) + 1 for v in vertices(g)]
@@ -74,6 +73,7 @@ end
     vertices(g), [ceil(Int64, first(v) * 0.5) for v in vertices(g)]
   )
   bit_map = BitMap(vertex_to_bit_map, vertex_to_dimension_map)
+  s = siteinds(g, bit_map)
 
   ψ_fx = cos_itn(s, bit_map; k=0.25 * Float64(pi), dimension=1)
   ψ_gy = sin_itn(s, bit_map; k=0.5 * Float64(pi), dimension=2)
@@ -98,7 +98,6 @@ end
 @testset "test differentiation_operator_on_3D_function" begin
   L = 60
   g = named_grid((L, 1))
-  s = siteinds("S=1/2", g)
 
   vertex_to_dimension_map = Dictionary(
     vertices(g), [(first(v) % 3) + 1 for v in vertices(g)]
@@ -107,6 +106,8 @@ end
     vertices(g), [ceil(Int64, first(v) / 3) for v in vertices(g)]
   )
   bit_map = BitMap(vertex_to_bit_map, vertex_to_dimension_map)
+  s = siteinds(g, bit_map)
+
   ψ_fx = sin_itn(s, bit_map; k=Float64(pi), dimension=1)
   ψ_gy = sin_itn(s, bit_map; k=Float64(pi), dimension=2)
   ψ_hz = sinh_itn(s, bit_map; k=Float64(pi), dimension=3)