Basic Usage

using QUBOTools

By loading the package with the using statement, only a few constants will be dumped in the namespace, most of them model types.

File I/O

To read and write models one should use the QUBOTools.read_model/QUBOTools.write_model API.

# File Path
path = joinpath(@__DIR__, "data", "problem.json")

model = QUBOTools.read_model(path)

QUBOTools Model
▷ Sense ………………… Min
▷ Domain ……………… BoolDomain
▷ Variables ……… 3

Density:
▷ Linear ………………  66.67%
▷ Quadratic ………  66.67%
▷ Total …………………  66.67%

There are no warm-start values.

There are no solutions available.

Info

The QUBOTools.read_model and QUBOTools.write_model methods will try to infer the file format from the file extension. The format can be manually set by passing an extra optional parameter after the source path. For more information, see File Formats.

Data Access

QUBOTools.description(model)

"Simple QUBO Problem"

QUBOTools.linear_terms(model) |> collect

2-element Vector{Pair{Int64, Float64}}:
 2 => 0.4
 3 => -4.4

QUBOTools.quadratic_terms(model) |> collect

2-element Vector{Pair{Tuple{Int64, Int64}, Float64}}:
 (1, 2) => -0.8
 (1, 3) => 6.0

Model Analysis

QUBOTools.density(model)

0.6666666666666666

File formats

Conversion between formats

One of the main functionalities of this package is to allow fast conversion from a QUBO file format to another. Achieving this is as simple as writing the loaded model but providing a different specification:

QUBOTools.write_model(stdout, model, QUBOTools.Qubist())