Cbc.jl is an interface to the COIN-OR Branch and Cut solver. It provides a complete interface to the low-level C API, as well as an implementation of the solver-independent MathProgBase and MathOptInterface API's.

Note: This wrapper is maintained by the JuliaOpt community and is not a COIN-OR project.

The package is registered in METADATA.jl and so can be installed with Pkg.add.

julia> import Pkg; Pkg.add("Cbc")

Cbc.jl will use BinaryProvider.jl to automatically install the Cbc binaries. This should work for both the official Julia binaries from https://julialang.org/downloads/ and source-builds.

To install custom built Clp binaries set the environmental variable JULIA_CBC_LIBRARY_PATH and call import Pkg; Pkg.build("Cbc"). For instance, if the libraries are installed in /opt/lib just call

ENV["JULIA_CBC_LIBRARY_PATH"] = "/opt/lib"
import Pkg; Pkg.build("Cbc")

If you do not want BinaryProvider to download the default binaries on install set JULIA_CBC_LIBRARY_PATH before calling import Pkg; Pkg.add("Cbc").

To switch back to the default binaries clear JULIA_CBC_LIBRARY_PATH and call import Pkg; Pkg.build("Cbc").

Use Cbc.Optimizer to use Cbc with JuMP:

using Cbc
using JuMP
model = Model(with_optimizer(Cbc.Optimizer, logLevel=1))

Options are solver-dependent, and unfortunately not well documented.

The following options are likely to be the most useful:

• seconds -- Solution timeout limit. (Must be a Float64)
• logLevel -- Set to 1 to enable solution output.
• maxSolutions -- Terminate after this many feasible solutions have been found.
• maxNodes -- Terminate after this many branch-and-bound nodes have been evaluated.
• allowableGap -- Terminate after optimality gap is less than this value (on an absolute scale).
• ratioGap -- Terminate after optimality gap is smaller than this relative fraction.
• threads -- Set the number of threads to use for parallel branch & bound

The complete list of parameters can be found by running the cbc executable and typing ? at the prompt.

The low-level C interface is available in the CbcCInterface submodule:

using Cbc.CbcCInterface

Using this interface is not recommended.