README.rdoc

Gurobi¶ ↑

This is a Gurobi Ruby binding based on C++ Gurobi API.

Prerequisites¶ ↑

• C++(g++) is installed.

• Gurobi 5.5 is installed.

• Environment variable GUROBI_HOME is set (e.g. /opt/gurobi550/linux64).

Installation¶ ↑

• From rubygems.org

  $ gem install gurobi

• From github

  1. download or ‘git clone’ like this:

     $ mkdir [YOUR_WORK_DIR]
     $ cd [YOUR_WORK_DIR]
     $ git clone https://github.com/fuminori-ido/gurobi.git

  2. rake build

     $ cd gurobi
     $ rake build

  3. install it

     $ gem install pkg/gurobi-N.NN.NN.gem      # replace N to actual version

Usage¶ ↑

Following model:

      x1, x2, x3 >=  0
              x3 <= 30
2*x1 +   x2 + x3 <= 60
  x1 + 2*x2 + x3 <= 60
maximize 15*x1 + 18*x2 + 30*x3

is written in following ruby code:

require 'gurobi'

model = Gurobi::Model.new(Gurobi::Env.new)
x1    = model.addVar(0, Gurobi::INFINITY, 0, Gurobi::CONTINUOUS, 'x1')
x2    = model.addVar(0, Gurobi::INFINITY, 0, Gurobi::CONTINUOUS, 'x2')
x3    = model.addVar(0, 30,               0, Gurobi::CONTINUOUS, 'x3')
model.update
model.addConstr(2*x1 +   x2 + x3 <= 60)
model.addConstr(  x1 + 2*x2 + x3 <= 60)
model.setObjective(15*x1 + 18*x2 + 30*x3, Gurobi::MAXIMIZE)
model.optimize
print "val = ", model.get_double(Gurobi::DoubleAttr::OBJ_VAL), "\n"
print "x1  = ", x1.get_double(Gurobi::DoubleAttr::X), "\n"
print "x2  = ", x2.get_double(Gurobi::DoubleAttr::X), "\n"
print "x3  = ", x3.get_double(Gurobi::DoubleAttr::X), "\n"

See spec/ and sample/ for more examples.

Document¶ ↑

1. generate document by:

   $ rake yard

2. browse doc/frames.html

TODO¶ ↑

• Some known memory leak exist.

• Client/Server model is not implemented.

Contributing¶ ↑

1. Fork it ( github.com/fuminori-ido/gurobi/fork )

2. Create your feature branch (‘git checkout -b my-new-feature`)

3. Commit your changes (‘git commit -am ’Add some feature’‘)

4. Push to the branch (‘git push origin my-new-feature`)

5. Create a new Pull Request