Cbc Ruby

Cbc - the mixed-integer programming solver - for Ruby

Check out Opt for a high-level interface

First, install Cbc. For Homebrew, use:

brew install cbc

And for Ubuntu, use:

sudo apt-get install coinor-libcbc3.1 # or coinor-libcbc3

Then add this line to your application’s Gemfile:

gem "cbc"

The API is fairly low-level at the moment

Load a problem

model =
  Cbc.load_problem(
    sense: :minimize,
    start: [0, 3, 6],
    index: [0, 1, 2, 0, 1, 2],
    value: [2, 3, 2, 2, 4, 1],
    col_lower: [0, 0],
    col_upper: [1e30, 1e30],
    obj: [8, 10],
    row_lower: [7, 12, 6],
    row_upper: [1e30, 1e30, 1e30],
    col_type: [:integer, :continuous]
  )

Solve

model.solve

Write the problem to an LP or MPS file (LP requires Cbc 2.10+)

model.write_lp("hello.lp")
# or
model.write_mps("hello") # adds .mps.gz

Read a problem from an LP or MPS file (LP requires Cbc 2.10+)

model = Cbc.read_lp("hello.lp")
# or
model = Cbc.read_mps("hello.mps.gz")

Set the log level (requires Cbc 2.10+)

model.solve(log_level: 1) # 0 = off, 3 = max

Set the time limit in seconds (requires Cbc 2.10+)

model.solve(time_limit: 30)

View the changelog

Everyone is encouraged to help improve this project. Here are a few ways you can help:

• Report bugs
• Fix bugs and submit pull requests
• Write, clarify, or fix documentation
• Suggest or add new features

To get started with development:

git clone https://github.com/ankane/cbc-ruby.git
cd cbc-ruby
bundle install
bundle exec rake test