Refactor initializeMPS (#180)

Rename initializeMPS to `initialize_mps` and add optional `f=randn` and `T=ComplexF64` args

Author: pbrehmer

examples/boundary_mps.jl

@@ -23,7 +23,7 @@ T = InfiniteTransferPEPS(peps, 1, 1)
 # encodes the norm of the state
 
 # Fist we build an initial guess for the boundary MPS, choosing a bond dimension of 20
-mps = PEPSKit.initializeMPS(T, [ComplexSpace(20)])
+mps = initialize_mps(T, [ComplexSpace(20)])
 
 # We then find the leading boundary MPS fixed point using the VUMPS algorithm
 mps, env, ϵ = leading_boundary(mps, T, VUMPS())
@@ -51,7 +51,7 @@ N´ = abs(norm(peps, ctm))
 peps2 = InfinitePEPS(ComplexSpace(2), ComplexSpace(2); unitcell=(2, 2))
 T2 = PEPSKit.MultilineTransferPEPS(peps2, 1)
 
-mps2 = PEPSKit.initializeMPS(T2, fill(ComplexSpace(20), 2, 2))
+mps2 = initialize_mps(T2, fill(ComplexSpace(20), 2, 2))
 mps2, env2, ϵ = leading_boundary(mps2, T2, VUMPS())
 N2 = abs(prod(expectation_value(mps2, T2)))
 
@@ -76,7 +76,7 @@ N2´ = abs(norm(peps2, ctm2))
 pepo = ising_pepo(1)
 T3 = InfiniteTransferPEPO(peps, pepo, 1, 1)
 
-mps3 = PEPSKit.initializeMPS(T3, [ComplexSpace(20)])
+mps3 = initialize_mps(T3, [ComplexSpace(20)])
 mps3, env3, ϵ = leading_boundary(mps3, T3, VUMPS())
 @show N3 = abs(prod(expectation_value(mps3, T3)))
 

src/PEPSKit.jl

@@ -89,7 +89,7 @@ export InfinitePartitionFunction
 export InfinitePEPS, InfiniteTransferPEPS
 export SUWeight, InfiniteWeightPEPS
 export InfinitePEPO, InfiniteTransferPEPO
-export initializeMPS, initializePEPS
+export initialize_mps, initializePEPS
 export ReflectDepth, ReflectWidth, Rotate, RotateReflect
 export symmetrize!, symmetrize_retract_and_finalize!
 export showtypeofgrad

src/operators/transfermatrix.jl

@@ -125,53 +125,59 @@ const MultilineTransferMatrix = Union{MultilineTransferPEPS,MultilineTransferPEP
 virtualspace(O::InfiniteTransferMatrix, i, dir) = virtualspace(O[i], dir)
 
 """
-    initializeMPS(
+    initialize_mps(
+        f=randn,
+        T=scalartype(O),
         O::Union{InfiniteTransferPEPS,InfiniteTransferPEPO},
         virtualspaces::AbstractArray{<:ElementarySpace,1}
     )
-    initializeMPS(
+    initialize_mps(
+        f=randn,
+        T=scalartype(O),
         O::Union{MultilineTransferPEPS,MultilineTransferPEPO},
         virtualspaces::AbstractArray{<:ElementarySpace,2}
     )
 
 Inialize a boundary MPS for the transfer operator `O` by specifying an array of virtual
 spaces consistent with the unit cell.
 """
-function initializeMPS(
-    O::InfiniteTransferMatrix, virtualspaces::AbstractArray{S,1}
+function initialize_mps(O::Union{InfiniteTransferMatrix,MultilineTransferMatrix}, arg) # initialize(f=randn, T=scalartype(O), O, ...)
+    return initialize_mps(randn, scalartype(O), O, arg)
+end
+function initialize_mps(
+    f, T, O::InfiniteTransferMatrix, virtualspaces::AbstractArray{S,1}
 ) where {S}
     return InfiniteMPS([
-        randn(
-            scalartype(O),
+        f(
+            T,
             virtualspaces[_prev(i, end)] * _elementwise_dual(north_virtualspace(O, i)),
             virtualspaces[mod1(i, end)],
         ) for i in 1:length(O)
     ])
 end
-function initializeMPS(O::InfiniteTransferMatrix, χ::Int)
+function initialize_mps(f, T, O::InfiniteTransferMatrix, χ::Int)
     return InfiniteMPS([
-        randn(calartype(O), ℂ^χ * _elementwise_dual(north_virtualspace(O, i)), ℂ^χ) for
-        i in 1:length(O)
+        f(T, ℂ^χ * _elementwise_dual(north_virtualspace(O, i)), ℂ^χ) for i in 1:length(O)
     ])
 end
-function initializeMPS(
-    O::MultilineTransferMatrix, virtualspaces::AbstractArray{S,2}
+function initialize_mps(
+    f, T, O::MultilineTransferMatrix, virtualspaces::AbstractArray{S,2}
 ) where {S}
     mpss = map(1:size(O, 1)) do r
-        return initializeMPS(O[r], virtualspaces[r, :])
+        return initialize_mps(f, T, O[r], virtualspaces[r, :])
     end
     return MPSKit.Multiline(mpss)
 end
-function initializeMPS(
-    O::MultilineTransferMatrix, virtualspaces::AbstractArray{S,1}
+function initialize_mps(
+    f, T, O::MultilineTransferMatrix, virtualspaces::AbstractArray{S,1}
 ) where {S}
-    return initializeMPS(O, repeat(virtualspaces, length(O), 1))
+    return initialize_mps(f, T, O, repeat(virtualspaces, length(O), 1))
 end
-function initializeMPS(O::MultilineTransferMatrix, V::ElementarySpace)
-    return initializeMPS(O, repeat([V], length(O), length(O[1])))
+function initialize_mps(f, T, O::MultilineTransferMatrix, V::ElementarySpace)
+    return initialize_mps(f, T, O, repeat([V], length(O), length(O[1])))
 end
-function initializeMPS(O::MultilineTransferMatrix, χ::Int)
-    return initializeMPS(O, repeat([ℂ^χ], length(O), length(O[1])))
+function initialize_mps(f, T, O::MultilineTransferMatrix, χ::Int)
+    return initialize_mps(f, T, O, repeat([ℂ^χ], length(O), length(O[1])))
 end
 
 @doc """

test/boundarymps/vumps.jl

@@ -7,13 +7,14 @@ using LinearAlgebra
 
 Random.seed!(29384293742893)
 
-const vumps_alg = VUMPS(; alg_eigsolve=MPSKit.Defaults.alg_eigsolve(; ishermitian=false))
-
+const vumps_alg = VUMPS(;
+    tol=1e-6, alg_eigsolve=MPSKit.Defaults.alg_eigsolve(; ishermitian=false), verbosity=2
+)
 @testset "(1, 1) PEPS" begin
     psi = InfinitePEPS(ComplexSpace(2), ComplexSpace(2))
 
     T = PEPSKit.InfiniteTransferPEPS(psi, 1, 1)
-    mps = PEPSKit.initializeMPS(T, [ComplexSpace(20)])
+    mps = initialize_mps(T, [ComplexSpace(20)])
 
     mps, env, ϵ = leading_boundary(mps, T, vumps_alg)
     N = abs(sum(expectation_value(mps, T)))
@@ -28,7 +29,7 @@ end
     psi = InfinitePEPS(ComplexSpace(2), ComplexSpace(2); unitcell=(2, 2))
     T = PEPSKit.MultilineTransferPEPS(psi, 1)
 
-    mps = PEPSKit.initializeMPS(T, fill(ComplexSpace(20), 2, 2))
+    mps = initialize_mps(rand, scalartype(T), T, fill(ComplexSpace(20), 2, 2))
     mps, env, ϵ = leading_boundary(mps, T, vumps_alg)
     N = abs(prod(expectation_value(mps, T)))
 
@@ -45,10 +46,10 @@ end
 
     psi = InfinitePEPS(D, d; unitcell=(1, 1))
     n = InfiniteSquareNetwork(psi)
-    T = PEPSKit.InfiniteTransferPEPS(psi, 1, 1)
+    T = InfiniteTransferPEPS(psi, 1, 1)
 
     # compare boundary MPS contraction to CTMRG contraction
-    mps = PEPSKit.initializeMPS(T, [χ])
+    mps = initialize_mps(T, [χ])
     mps, env, ϵ = leading_boundary(mps, T, vumps_alg)
     N_vumps = abs(prod(expectation_value(mps, T)))
 
@@ -100,7 +101,7 @@ end
     psi = PEPSKit.initializePEPS(O, ComplexSpace(2))
     T = InfiniteTransferPEPO(psi, O, 1, 1)
 
-    mps = PEPSKit.initializeMPS(T, [ComplexSpace(10)])
+    mps = initialize_mps(rand, scalartype(T), T, [ComplexSpace(10)])
     mps, env, ϵ = leading_boundary(mps, T, vumps_alg)
     f = abs(prod(expectation_value(mps, T)))
 
@@ -109,7 +110,7 @@ end
     psi2 = initializePEPS(O, ComplexSpace(2))
     T = InfiniteTransferPEPO(psi, O, 1, 1)
 
-    mps = PEPSKit.initializeMPS(T, [ComplexSpace(8)])
+    mps = initialize_mps(rand, scalartype(T), T, [ComplexSpace(8)])
     mps, env, ϵ = leading_boundary(mps, T, vumps_alg)
     f = abs(prod(expectation_value(mps, T)))
 end