Bump to v0.5.4

Project.toml

@@ -1,7 +1,7 @@
 name = "PartitionedMPSs"
 uuid = "17ce1de9-5131-45e3-8a48-9723b6e2dc23"
 authors = ["Hiroshi Shinaoka <[email protected]> and contributors"]
-version = "0.5.3"
+version = "0.5.4"
 
 [deps]
 Coverage = "a2441757-f6aa-5fb2-8edb-039e3f45d037"

src/partitionedmps.jl

@@ -112,6 +112,21 @@ Add two PartitionedMPS objects.
 If the two projects have the same projectors in the same order, the resulting PartitionedMPS will have the same projectors in the same order.
 By default, we use `directsum` algorithm to compute the sum and no truncation is performed.
 """
+function Base.:+(
+    partmpss::PartitionedMPS...;
+    alg="directsum",
+    cutoff=0.0,
+    maxdim=typemax(Int),
+    coeffs=ones(length(partmpss)),
+    kwargs...,
+)::PartitionedMPS
+    result = PartitionedMPS()
+    for (coeff, partmps) in zip(coeffs, partmpss)
+        result = +(result, coeff * partmps; alg, cutoff, maxdim, kwargs...)
+    end
+    return result
+end
+
 function Base.:+(
     a::PartitionedMPS,
     b::PartitionedMPS;
@@ -182,6 +197,7 @@ function truncate(
     cutoff=default_cutoff(),
     maxdim=default_maxdim(),
     use_adaptive_weight=true,
+    maxrefinement=4,
     kwargs...,
 )::PartitionedMPS
     norm2 = [LinearAlgebra.norm(v)^2 for v in values(obj)]
@@ -190,7 +206,7 @@ function truncate(
 
     compressed = obj
 
-    while true
+    for _ in 1:maxrefinement
         compressed = PartitionedMPS([
             truncate(v; cutoff=cutoff * w, maxdim, kwargs...) for
             (v, w) in zip(values(obj), weights)
@@ -200,7 +216,7 @@ function truncate(
             break
         end
 
-        weights .*= cutoff / actual_error # Adjust weights
+        weights .*= min(cutoff / actual_error, 0.5) # Adjust weights
     end
 
     return compressed

src/projector.jl

@@ -43,6 +43,7 @@ end
 projectedinds(p::Projector) = p.data
 
 Base.getindex(p::Projector, inds) = p.data[inds]
+Base.getindex(p::Projector, ind, default) = get(p.data, ind, default)
 Base.keys(p::Projector) = keys(p.data)
 
 function Base.iterate(obj::Projector, state)

src/subdomainmps.jl

@@ -66,6 +66,18 @@ function project(projΨ::SubDomainMPS, projector::Projector)::Union{Nothing,SubD
     )
 end
 
+function project(
+    projΨ::SubDomainMPS, pairs::Vararg{Pair{Index{T},Int}}
+)::Union{Nothing,SubDomainMPS} where {T}
+    return project(projΨ, Projector(pairs...))
+end
+
+function project(
+    Ψ::AbstractMPS, pairs::Vararg{Pair{Index{T},Int}}
+)::Union{Nothing,SubDomainMPS} where {T}
+    return project(Ψ, Projector(pairs...))
+end
+
 function project(Ψ::AbstractMPS, projector::Projector)::Union{Nothing,SubDomainMPS}
     return project(SubDomainMPS(Ψ), projector)
 end

test/partitionedmps_tests.jl

@@ -65,6 +65,20 @@ import PartitionedMPSs: PartitionedMPSs, Projector, project, SubDomainMPS, Parti
         @test MPS((a + b) + 2 * (b + a)) ≈ 3 * Ψ rtol = 1e-13
     end
 
+    @testset "add" begin
+        Random.seed!(1234)
+        N = 3
+        d = 10
+        sites = [Index(d, "x=$n") for n in 1:N]
+        Ψ = MPS(collect(_random_mpo([[s] for s in sites])))
+
+        projectors = [Projector(sites[1] => d_) for d_ in 1:d]
+        coeffs = rand(length(projectors))
+        prjΨs = [project(Ψ, p) for p in projectors]
+
+        @test MPS(+([PartitionedMPS(x) for x in prjΨs]...; coeffs=coeffs)) ≈ +([c * MPS(x) for (c, x) in zip(coeffs, prjΨs)]...; alg="directsum")
+    end
+
     @testset "truncate" begin
         for seed in [1, 2, 3, 4, 5]
             Random.seed!(seed)