COIN-OR

Raku interface to the COIN-OR numerical optimization solver.

The initial API wraps CBC's portable C interface through Raku NativeCall. It supports constructing and solving linear mixed-integer models; see examples listed below.

For large, sparse constraint matrices, use Model.load-problem rather than adding rows one at a time. It accepts CBC's compressed sparse column (CSC) format: starts has one offset per column plus a final offset, while indexes and values hold the row index and coefficient of each nonzero.

my $model = COIN-OR::Model.new(:name<csc-example>);
$model.load-problem(
    :columns(2), :rows(1),
    :starts([0, 1, 2]), :indexes([0, 0]), :values([1e0, 1e0]),
    :column-upper([2e0, 3e0]), :objective([3e0, 2e0]),
    :row-upper([4e0]), :integer-columns([0, 1]),
);
$model.maximize;
$model.solve;

add-row is already sparse: its column-index and coefficient lists contain only the nonzero entries of that row. CBC's C interface has no Cbc_addSparseRow; Cbc_loadProblem is its bulk sparse-matrix API.

Installation

macOS

#!/bin/bash

# Ensure Homebrew is up to date
brew update

# Install all 4 core COIN-OR packages
brew install coinutils clp cbc ipopt

# Verify installations
echo -e "\n--- Verification ---"
for cmd in cbc clp ipopt; do
  if command -v $cmd &> /dev/null; then
    echo "✅ $cmd installed: $($cmd --version 2>&1 | head -n 1)"
  else
    echo "❌ $cmd failed to install"
  fi
done

Homebrew installs formulae below an architecture-dependent prefix (normally /opt/homebrew on Apple Silicon and /usr/local on Intel). Configure the binding with either of these optional environment variables before running Raku:

# Recommended: ask Homebrew for the exact CBC C-interface library.
export COIN_OR_CBC_LIBRARY="$(brew --prefix cbc)/lib/libCbcSolver.dylib"

# Alternative: provide the containing directory; the package chooses
# libCbcSolver.dylib on macOS (and libCbcSolver.so on Linux).
export COIN_OR_LIBRARY_DIR="$(brew --prefix cbc)/lib"

COIN_OR_CBC_LIBRARY takes precedence over COIN_OR_LIBRARY_DIR. Neither is needed on a system where the dynamic linker can already locate libCbcSolver. For a persistent macOS configuration, add the preferred export line to ~/.zprofile (zsh's login-shell configuration) and start a new terminal.

Ubuntu Linux

sudo apt update
# Install CBC (Mixed-Integer Linear Programming Solver)
sudo apt install coinor-cbc coinor-libcbc-dev

# Install CLP (Linear Programming Solver)
sudo apt install coinor-clp coinor-libclp-dev

# Install Ipopt (Nonlinear Programming Solver)
sudo apt install coinor-ipopt coinor-libipopt-dev

Raku package

From Zef ecosystem:

zef install COIN-OR

From GitHub:

zef install https://github.com/antononcube/Raku-COIN-OR

Installation scripts

With Raku and zef already installed, the local distribution can be installed with its CBC dependencies using:

sh resources/install.sh

The script supports macOS (Homebrew) and Linux (APT or Pacman). On Windows, install MSYS2 and Raku with zef, then run from PowerShell:

.\resources\install-windows.ps1

Examples

Here are Raku scripts with worked examples:

• (Very) simple model

• Solving a Linear Programming (LP) problem

• Solving Stingler's diet

• Assignment problem