Version 17 (modified by pbelotti, 13 years ago) (diff)


Couenne, an exact solver for nonconvex MINLPs

Couenne (Convex Over and Under ENvelopes for Nonlinear Estimation) is a branch&bound algorithm to solve Mixed-Integer Nonlinear Programming (MINLP) problems. Its purpose is to find global optima of nonconvex MINLPs.

Couenne implements linearization, bound reduction, and sophisticated branching methods within a Branch&Bound framework. Its main components are:

  • an expression library;
  • separation of linearization cuts;
  • branching rules;
  • bound tightening methods.

It is distributed on Coin-OR ( under the CPL (Common Public License). The CPL is a license approved by the OSI (Open Source Initiative), thus Couenne is OSI Certified Open Source Software.

Download, installation and usage

Couenne is found on the COIN-OR project page. It can be downloaded with Subversion -- see also some instructions on using svn. Run the command:

svn co Couenne

to get the source code. Before building and installing Couenne, you need to obtain some third party packages. These cannot be downloaded from COIN-OR, and have to be dowloaded independently. These packages are: ASL, Blas, Lapack, and HSL. The user is referred to the INSTALL file in each of the subdirectories of ThirdParty/? for instructions on how to obtain them.

To install Couenne, we refer to general installation instructions for COIN-OR projects. The impatient may want to issue the following commands:

cd Couenne
mkdir build
cd build
../configure -C
make install

The above commands place Couenne in the Couenne/build/bin/ directory, libraries in Couenne/build/lib/, and include files in Couenne/build/include/. An alternative directory can be specified with the --prefix option of configure. For instance, when replacing "../configure -C" above with

../configure -C --prefix=/usr/local

the Couenne executable will be installed in /usr/local/bin/, the libraries in /usr/local/lib/, and the include files in /usr/local/include/.

Couenne is run as follows:


where is an AMPL stub (.nl) file. Such files can be generated from AMPL with the command "write gfilename;" (notice the "g" before the file name), for example.

You may also specify a set of options to tweak the performance of Couenne.

Couenne is maintained by Pietro Belotti (belotti at lehigh dot edu).

Web page:

Dependencies: CoinUtils, Cbc, Cgl, Clp, Ipopt, and Osi (from Coin-OR); ASL (the Ampl Solver Library), Lapack, Blas, and HSL.

External resources: Coin-OR, Common Public License.

Improve this page, report a bug, contribute to Couenne

As an open-source code, contributions to Couenne are welcome. To submit a contribution to Couenne, please follow the COIN-OR guidelines.

In order to report a bug, use the ticket system. All you need to do is

  1. Register and login,
  2. Create a ticket.

As all Wiki pages, this page is editable: you can easily modify its contents with your web browser. First register and login, then click on the "Edit this page" link at the bottom of the page. WikiFormatting gives you a detailed description of available Wiki formatting commands.



This project was initiated in 2006 within a collaboration between IBM and Carnegie Mellon University, aimed at developing algorithms for MINLP.

Credit should be given to our colleagues in this collaboration: Andreas, Pierre, and Stefan, who developed part of Couenne, and Larry T. Biegler, Gérard Cornuéjols, Ignacio E. Grossmann, Jon Lee, and François Margot.

Each has contributed an essential part of the development of Couenne.