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ConstraintModels.jl

Documentation for ConstraintModels.jl.

ConstraintModels.SudokuInstance Type
julia
mutable struct SudokuInstance{T <: Integer} <: AbstractMatrix{T}

A struct for SudokuInstances, which is a subtype of AbstractMatrix.

julia
SudokuInstance(A::AbstractMatrix{T})
SudokuInstance(::Type{T}, n::Int) # fill in blank sudoku of type T
SudokuInstance(n::Int) # fill in blank sudoku of type Int
SudokuInstance(::Type{T}) # fill in "standard" 9×9 sudoku of type T
SudokuInstance() # fill in "standard" 9×9 sudoku of type Int
SudokuInstance(n::Int, P::Pair{Tuple{Int, Int}, T}...) where {T <: Integer} # construct a sudoku given pairs of coordinates and values
SudokuInstance(P::Pair{Tuple{Int, Int}, T}...) # again, default to 9×9 sudoku, constructing given pairs

Constructor functions for the SudokuInstance struct.

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ConstraintModels.SudokuInstance Method
julia
SudokuInstance(X::Dictionary)

Construct a SudokuInstance with the values X of a solver as input.

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Base.Multimedia.display Method
julia
display(io::IO, S::SudokuInstance)
display(S::SudokuInstance) # default to stdout

Displays an n×n SudokuInstance.

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Base.Multimedia.display Method
julia
Base.display(X, Val(:sudoku))

Extends Base.display to a sudoku configuration.

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Base.Multimedia.display Method
julia
Base.display(S::SudokuInstance)

Extends Base.display to SudokuInstance.

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Base.Multimedia.display Method
julia
Base.display(X::Dictionary)

Extends Base.display to a sudoku configuration.

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Base.size Method
julia
Base.size(S::SudokuInstance)

Extends Base.size for SudokuInstance.

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ConstraintModels._format_line Method
julia
_format_line(r, M)

Format line of a sudoku grid.

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ConstraintModels._format_line_segment Method
julia
_format_line_segment(r, col_pos, M)

Format line segment of a sudoku grid.

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ConstraintModels._format_val Method
julia
_format_val(a)

Format an integer a into a string for SudokuInstance.

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ConstraintModels._get_sep_line Method
julia
_get_sep_line(s, pos_row, M)

Return a line separator.

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ConstraintModels.chemical_equilibrium Method
julia
chemical_equilibrium(atoms_compounds, elements_weights, standard_free_energy; modeler = :JuMP)

Warning

Even the structure to model problems with continuous domains is available, the default solver is not yet equiped to solve such problems efficiently.

From Wikipedia

In a chemical reaction, chemical equilibrium is the state in which both the reactants and products are present in concentrations which have no further tendency to change with time, so that there is no observable change in the properties of the system. This state results when the forward reaction proceeds at the same rate as the reverse reaction. The reaction rates of the forward and backward reactions are generally not zero, but they are equal. Thus, there are no net changes in the concentrations of the reactants and products. Such a state is known as dynamic equilibrium.

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ConstraintModels.golomb Function
julia
golomb(n, L=n²)

Model the Golomb problem of n marks on the ruler 0:L. The modeler argument accepts :raw, and :JuMP (default), which refer respectively to the solver internal model, the MathOptInterface model, and the JuMP model.

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ConstraintModels.magic_square Method
julia
magic_square(n; modeler = :JuMP)

Create a model for the magic square problem of order n. The modeler argument accepts :JuMP (default), which refer to the solver the JuMP model.

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ConstraintModels.mincut Method
julia
mincut(graph; source, sink, interdiction =0, modeler = :JuMP)

Compute the minimum cut of a graph.

Arguments:

  • graph: Any matrix <: AbstractMatrix that describes the capacities of the graph

  • source: Id of the source node; must be set

  • sink: Id of the sink node; must be set

  • interdiction: indicates the number of forbidden links

  • modeler: Default to :JuMP.

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ConstraintModels.n_queens Method
julia
n_queens(n; modeler = :JuMP)

Create a model for the n-queens problem with n queens. The modeler argument accepts :JuMP (default), which refer to the JuMP model.

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ConstraintModels.qap Method
julia
qap(n, weigths, distances; modeler = :JuMP)

Modelize an instance of the Quadractic Assignment Problem with

  • n: number of both facilities and locations

  • weights: Matrix of the weights of each pair of facilities

  • distances: Matrix of distances between locations

  • modeler: Default to :JuMP. No other modeler available for now.

From Wikipedia

There are a set of n facilities and a set of n locations. For each pair of locations, a distance is specified and for each pair of facilities a weight or flow is specified (e.g., the amount of supplies transported between the two facilities). The problem is to assign all facilities to different locations with the goal of minimizing the sum of the distances multiplied by the corresponding flows.

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ConstraintModels.sudoku Method
julia
sudoku(n; start= Dictionary{Int, Int}(), modeler = :JuMP)

Create a model for the sudoku problem of domain 1:n² with optional starting values. The modeler argument accepts :raw, :MOI, and :JuMP (default), which refer respectively to the solver internal model, the MathOptInterface model, and the JuMP model.

julia
# Construct a JuMP model `m` and its associated matrix `grid` for sudoku 9×9
m, grid = sudoku(3)

# Same with a starting instance
instance = [
    9  3  0  0  0  0  0  4  0
    0  0  0  0  4  2  0  9  0
    8  0  0  1  9  6  7  0  0
    0  0  0  4  7  0  0  0  0
    0  2  0  0  0  0  0  6  0
    0  0  0  0  2  3  0  0  0
    0  0  8  5  3  1  0  0  2
    0  9  0  2  8  0  0  0  0
    0  7  0  0  0  0  0  5  3
]
m, grid = sudoku(3, start = instance)

# Run the solver
optimize!(m)

# Retrieve and display the values
solution = value.(grid)
display(solution, Val(:sudoku))

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