Merge pull request #4 from psrenergy/px/qubotools-v1

Create `DWave.Neal` Module

CondaPkg.toml

@@ -4,7 +4,6 @@ channels = ["anaconda", "conda-forge"]
 python = ">=3.7,<=3.11"
 
 [pip.deps]
-# numpy           = ">=1.20"
-# matplotlib      = ">=3.5"
+numpy           = ">=1.20"
 dwave-ocean-sdk = "==6.4.1"
 dwave_networkx  = "==0.8.14"

Project.toml

@@ -1,13 +1,19 @@
 name = "DWave"
 uuid = "4d534982-bf11-4157-9e48-fe3a62208a50"
 authors = ["pedromxavier <[email protected]>", "pedroripper <[email protected]>"]
-version = "0.4.0"
+version = "0.4.1"
 
 [deps]
+Graphs = "86223c79-3864-5bf0-83f7-82e725a168b6"
+MathOptInterface = "b8f27783-ece8-5eb3-8dc8-9495eed66fee"
 PythonCall = "6099a3de-0909-46bc-b1f4-468b9a2dfc0d"
 QUBODrivers = "a3f166f7-2cd3-47b6-9e1e-6fbfe0449eb0"
+QUBOTools = "60eb5b62-0a39-4ddc-84c5-97d2adff9319"
 
 [compat]
-PythonCall = "0.9.14"
+Graphs = "1"
+MathOptInterface = "1"
+PythonCall = "0.9.15"
 QUBODrivers = "0.3"
+QUBOTools = "0.9"
 julia = "1.9"

src/DWave.jl

@@ -1,41 +1,50 @@
 module DWave
 
+import Graphs
+import QUBOTools
 import QUBODrivers
-import QUBODrivers: MOI, QUBOTools
+import MathOptInterface as MOI
 
 using PythonCall
 
 # -*- :: Python D-Wave Module :: -*- #
-# const np  = PythonCall.pynew()
-# const plt = PythonCall.pynew()
+const np              = PythonCall.pynew()
 const dwave_cloud     = PythonCall.pynew()
 const dwave_dimod     = PythonCall.pynew()
 const dwave_embedding = PythonCall.pynew()
 const dwave_networkx  = PythonCall.pynew()
 const dwave_system    = PythonCall.pynew()
 
-function __init__()
-    # Python Packages
-    # PythonCall.pycopy!(np, pyimport("numpy"))
-    # PythonCall.pycopy!(plt, pyimport("matplotlib.pyplot"))
-    PythonCall.pycopy!(dwave_cloud, pyimport("dwave.cloud"))
-    PythonCall.pycopy!(dwave_dimod, pyimport("dimod"))
-    PythonCall.pycopy!(dwave_embedding, pyimport("dwave.embedding"))
-    PythonCall.pycopy!(dwave_networkx, pyimport("dwave_networkx"))
-    PythonCall.pycopy!(dwave_system, pyimport("dwave.system"))
-
+function __auth__()
     # D-Wave API Credentials
     if !haskey(ENV, "DWAVE_API_TOKEN")
         @warn """
-        The 'DWAVE_API_TOKEN' environment variable is not defined. Please, make sure that another access method is available.
+        The 'DWAVE_API_TOKEN' environment variable is not defined.
+        If you want to use D-Wave's cloud services, please make sure that another access method is available.
         
         For more information visit:
             https://docs.ocean.dwavesys.com/en/stable/overview/sapi.html
         """
     end
+
+    return nothing
+end
+
+function __init__()
+    # Python Packages
+    PythonCall.pycopy!(np, pyimport("numpy"))
+    PythonCall.pycopy!(dwave_cloud, pyimport("dwave.cloud"))
+    PythonCall.pycopy!(dwave_dimod, pyimport("dimod"))
+    PythonCall.pycopy!(dwave_embedding, pyimport("dwave.embedding"))
+    PythonCall.pycopy!(dwave_networkx, pyimport("dwave_networkx"))
+    PythonCall.pycopy!(dwave_system, pyimport("dwave.system"))
+
+    __auth__()
+
+    return nothing
 end
 
 include("sampler.jl")
-include("neal.jl")
+include("neal/sampler.jl")
 
 end # module

src/neal.jl → src/neal/sampler.jl

@@ -1,7 +1,8 @@
 module Neal
 
+import QUBOTools
 import QUBODrivers
-import QUBODrivers: MOI, QUBOTools 
+import MathOptInterface as MOI
 
 using PythonCall
 
@@ -12,18 +13,6 @@ function __init__()
     PythonCall.pycopy!(neal, pyimport("neal"))
 end
 
-const ATTRIBUTES = [
-    :num_reads,
-    :num_sweeps,
-    :num_sweeps_per_beta,
-    :beta_range,
-    :beta_schedule,
-    :beta_schedule_type,
-    :seed,
-    :initial_states_generator,
-    :interrupt_function,
-]
-
 @doc raw"""
     DWave.Neal.Optimizer
 
@@ -51,8 +40,15 @@ function QUBODrivers.sample(sampler::Optimizer{T}) where {T}
 
     # Retrieve Optimizer Attributes
     params = Dict{Symbol,Any}(
-        param => MOI.get(sampler, MOI.RawOptimizerAttribute(string(param)))
-        for param in ATTRIBUTES
+        :num_reads => MOI.get(sampler, MOI.RawOptimizerAttribute("num_reads")),
+        :num_sweeps => MOI.get(sampler, MOI.RawOptimizerAttribute("num_sweeps")),
+        :num_sweeps_per_beta => MOI.get(sampler, MOI.RawOptimizerAttribute("num_sweeps_per_beta")),
+        :beta_range => MOI.get(sampler, MOI.RawOptimizerAttribute("beta_range")),
+        :beta_schedule => MOI.get(sampler, MOI.RawOptimizerAttribute("beta_schedule")),
+        :beta_schedule_type => MOI.get(sampler, MOI.RawOptimizerAttribute("beta_schedule_type")),
+        :seed => MOI.get(sampler, MOI.RawOptimizerAttribute("seed")),
+        :initial_states_generator => MOI.get(sampler, MOI.RawOptimizerAttribute("initial_states_generator")),
+        :interrupt_function => MOI.get(sampler, MOI.RawOptimizerAttribute("interrupt_function")),
     )
 
     # Call D-Wave Neal API

src/wrapper/QUBOTools_DWave.jl

@@ -0,0 +1,3 @@
+module QUBOTools_DWave
+
+end

src/wrapper/README.md

@@ -0,0 +1,3 @@
+# D-Wave
+
+This folder constains specific interface definitions related to D-Wave hardware.

src/wrapper/architecture.jl

@@ -0,0 +1,8 @@
+@doc raw"""
+    DWaveArchitecture
+"""
+abstract type DWaveArchitecture <: QUBOTools.AbstractArchitecture end
+
+include("device.jl")
+include("chimera.jl")
+include("hfs/format.jl")

src/wrapper/chimera.jl

@@ -0,0 +1,170 @@
+# NOTE: This file is temporary. In the future, it should be moved to the
+# DWave.jl package, so that this functionality is activated only given a
+# specific context of use.
+
+@doc raw"""
+    Chimera
+    
+The format of the instance-description file starts with a line giving the size of the Chimera graph[^alex1770].
+Two numbers are given to specify an ``m \times n`` rectangle, but currently only a square (``m = n``) is accepted.
+
+The subsequent lines are of the form
+```
+    <Chimera vertex> <Chimera vertex> <weight>
+```
+where `<Chimera vertex>` is specified by four numbers using the format, Chimera graph, ``C_N``:
+    
+Vertices are ``v = (x, y, o, i)`` where
+- ``x, y \in [0, N - 1]`` are the horizontal, vertical coordinates of the ``K_{4, 4}``
+- ``o \in [0, 1]`` is the **orientation**: (``0 = \text{horizontally connected}``, ``1 = \text{vertically connected}``)
+- ``i \in [0, 3]`` is the index within the "semi-``K_{4,4}``" or "bigvertex"
+- There is an involution given by ``x \iff y``, ``o \iff 1 - o``
+
+There is an edge from ``v_p`` to ``v_q`` if at least one of the following holds:
+- ``(x_p, y_p) = (x_q, y_q) \wedge o_p \neq o_q``
+- ``|x_p - x_q| = 1 \wedge y_p = y_q \wedge o_p = o_q = 0 \wedge i_p = i_q``
+- ``x_p = x_q \wedge |y_p-y_q| = 1 \wedge o_p = o_q = 1 \wedge i_p = i_q``
+
+[^alex1770]:
+    `alex1770`'s QUBO-Chimera Git Repository [{git}](https://github.com/alex1770/QUBO-Chimera)
+
+[^dwave]:
+    **D-Wave QPU Architecture: Topologies** [{docs}](https://docs.dwavesys.com/docs/latest/c_gs_4.html)
+"""
+struct Chimera <: DWaveArchitecture
+    grid_size::NTuple{2,Int}
+    cell_size::Int
+    precision::Int
+    coordinates::Dict{Int,NTuple{4,Int}}
+    degree::Int
+    effective_degree::Int
+end
+
+function Chimera(
+    m::Integer = 2_048, # 2000Q
+    n::Integer = m;
+    cell_size::Integer = 8,
+    precision::Integer = 5,
+    degree::Union{Integer,Nothing} = nothing, 
+)
+    @assert m > 0
+    @assert n > 0
+    @assert m == n # TODO: relax
+
+    grid_size = (m, n)
+    dimension = m * n
+
+    min_degree = ceil(Int, sqrt(dimension / cell_size))
+
+    if isnothing(degree)
+        degree = min_degree
+    end
+
+    if degree < min_degree
+        error(
+            """
+            Error: degree of '$(degree)' was specified.
+            However, the minimum degree required for a system with '$(dimension)' sites is '$(min_degree)'.
+            """,
+        )
+    end
+
+    cell_row_size = cell_size ÷ 2
+
+    # These values are used to transform a variable index into a chimera 
+    # coordinate (x,y,o,i)
+    # x - row
+    # y - col
+    # o - cell_col - indicates the first or the second row of a chimera cell
+    # i - cell_col_id - indicates ids within a chimera cell
+    # Note that knowing the size of source chimera graph is essential to doing this mapping correctly
+
+    cell        = Dict{Int,Int}(i => (i ÷ cell_size) for i in 1:dimension)
+    row         = Dict{Int,Int}(i => (j ÷ degree) for (i, j) in cell)
+    col         = Dict{Int,Int}(i => (j % degree) for (i, j) in cell)
+    cell_col    = Dict{Int,Int}(i => (i % cell_size) ÷ cell_row_size for i in 1:dimension)
+    cell_col_id = Dict{Int,Int}(i => (i % cell_row_size) for i in 1:dimension)
+
+    coordinates = Dict{Int,NTuple{4,Int}}(
+        i => (row[i], col[i], cell_col[i], cell_col_id[i])
+        for i in 1:dimension
+    )
+
+    # Get the maximum of both row id and column id (namely 'c[1]', 'c[2]')
+    effective_degree = 1 + maximum((_, c) -> max(c[1], c[2]), coordinates)
+
+    if effective_degree > degree
+        error(
+            """
+            The effective degree '$effective_degree' value is greater than the chimera degree '$(degree)', which is infeasible.
+            """,
+        )
+    end
+
+    return Chimera(
+        grid_size,
+        cell_size,
+        precision,
+        coordinates,
+        degree,
+        effective_degree,
+    )
+end
+
+function DWaveDevice(arch::Chimera, model::QUBOTools.AbstractModel{V}) where {V}
+    L = collect(QUBOTools.linear_terms(model))
+    Q = collect(QUBOTools.quadratic_terms(model))
+    α = QUBOTools.scale(model)
+    β = QUBOTools.offset(model)
+
+    γ = max( # maximum absolute value for a coefficient in 'model'
+        maximum((_, v) -> abs(v), L),
+        maximum((_, v) -> abs(v), Q),
+    )
+
+    γχ =  10 ^ arch.precision / γ
+
+    # Chimera Coefficients
+    Lχ = sizehint!(Dict{V,Int}(), length(L))
+    Qχ = sizehint!(Dict{Tuple{V,V},Int}(), length(Q))
+
+    for (i, v) in L
+        xi = QUBOTools.variable(model, i) 
+
+        Lχ[xi] = round(Int, v * αχ)
+    end
+
+    for ((i, j), v) in Q
+        xi = QUBOTools.variable(model, i)
+        xj = QUBOTools.variable(model, j)
+
+        Qχ[(xi, xj)] = round(Int, v * αχ)
+    end
+
+    αχ = 1
+    βχ = round(Int, β * γχ)
+
+    factor = α * γχ
+
+    return DWaveDevice(
+        arch,
+        QUBOTools.Model{V,Int,Int}(
+            Set{V}(QUBOTools.variables(model)),
+            Lχ,
+            Qχ;
+            scale    = αχ,
+            offset   = βχ,
+            sense    = QUBOTools.sense(model),
+            domain   = QUBOTools.domain(model),
+            metadata = copy(QUBOTools.metadata(model)),
+            start    = QUBOTools.start(model),
+        ),
+        factor,
+    )
+end
+
+function layout(arch::Chimera)
+    # TODO: Retrieve this information from dwave-networkx?
+
+    return nothing
+end

src/wrapper/device.jl

@@ -0,0 +1,20 @@
+# NOTE: This file is temporary. In the future, it should be moved to the
+# DWave.jl package, so that this functionality is activated only given a
+# specific context of use.
+
+struct DWaveDevice{A<:DWaveArchitecture,V} <: QUBOTools.AbstractDevice{A,V,Int,Int}
+    arch::A
+    model::QUBOTools.Model{V,Int,Int}
+    factor::Float64
+
+    function DWaveDevice(
+        arch::A,
+        model::QUBOTools.Model{V,Int,Int},
+        factor::Float64 = 1.0,
+    ) where {A<:DWaveArchitecture,V}
+        return new{A,V}(arch, model, factor)
+    end
+end
+
+QUBOTools.architecture(dev::DWaveDevice) = dev.arch
+QUBOTools.backend(dev::DWaveDevice)      = dev.model

src/wrapper/hfs/format.jl

@@ -0,0 +1,20 @@
+@doc raw"""
+    HFS(;
+        chimera_cell_size::Union{Integer,Nothing} = nothing,
+        chimera_precision::Union{Integer,Nothing} = nothing,
+        chimera_degree::Union{Integer,Nothing}    = nothing,
+    )
+
+This format offers a description for the setup of chimera graphs.
+"""
+struct HFS <: AbstractFormat
+    chimera::Chimera
+
+    function HFS(chimera::Chimera)
+        return new(chimera)
+    end
+end
+
+format(::Val{:hfs}) = HFS(Chimera())
+
+include("printer.jl")