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Clp (Coin-or linear programming) is an open-source linear programming solver. It is primarily meant to be used as a callable library, but a basic, stand-alone executable version is also available. It is designed to find solutions of mathematical optimization problems of the form
minimize c'x such that lhs ≤ Ax ≤ rhs and lb ≤ x ≤ ub
CLP includes primal and dual Simplex solvers. Both dual and primal algorithms can use matrix storage methods provided by the user (0-1 and network matrices are already supported in addition to the default sparse matrix). The dual algorithm has Dantzig and Steepest edge row pivot choices; new ones may be provided by the user. The same is true for the column pivot choice of the primal algorithm. The primal can also use a non linear cost which should work for piecewise linear convex functions. CLP also includes a barrier method for solving LPs.
Clp is written in C++ and is released as open source under the Eclipse Public License 2.0.
It is distributed under the auspices of the COIN-OR Foundation.
The Clp development site is https://github.com/coin-or/Clp.
What follows is a quick start guide for obtaining or building Clp on common platforms. More detailed information is available here.
Linux (see https://repology.org/project/coin-or-clp/versions for a complete listing):
$ sudo pacman -S coin-or-clp
$ sudo apt-get install coinor-clp coinor-libclp-dev
$ sudo yum install coin-or-Clp coin-or-Clp-devel
$ sudo pkg install math/clp
$ brew install clp
Windows: The easiest way to get Clp on Windows is to download an archive as described above.
Mac OS X: The easiest way to get Clp on Mac OS X is through Homebrew.
$ brew tap coin-or-tools/coinor $ brew install coin-or-tools/coinor/clp
conda (cross-platform, no Windows for now):
$ conda install coin-or-clp
Due to license incompatibilities, pre-compiled binaries lack some functionality. If binaries are not available for your platform for the latest version and you would like to request them to be built and posted, feel free to let us know on the mailing list.
Source code can be obtained either by
- Downloading a snapshot of the source code for the latest release version of Clp from the releases page,
- Cloning this repository from Github, or
- Using the coinbrew script to get the project and all dependencies (recommended, see below).
Clp has a number of dependencies, which are detailed in
config.yml. Dependencies on other COIN-OR projects are
automatically downloaded when obtaining the source with
coinbrew. For some
of the remaining third-party dependencies, automatic download scripts and
build wrappers are provided (and will also be automatically run for required
and recommended dependencies), while other libraries that are aeasy to obtain
must be installed using an appropriate package manager (or may come with your
OS by default).
These quick start instructions assume you are in a bash shell.
To download and build Clp from source, execute the following on the command line.
wget https://raw.githubusercontent.com/coin-or/coinbrew/master/coinbrew chmod u+x coinbrew ./coinbrew fetch Clp@master ./coinbrew build Clp
- Download the source code, e.g., by cloning the git repo https://github.com/coin-or/Clp
- Download and install the source code for the dependencies listed in config.yml
- Build the code as follows (make sure to set PKG_CONFIG_PTH to install directory for dependencies).
./configure -C make make test make install
For Microsoft Visual C++ users, there are project files for version 10
available in the
MSVisualStudio directory. First, obtain the source code
using either a Windows git client or download a snapshot. In MSVC++ Version
10, open the solution file (this should be converted to whatever version of
MSVC+ you are using) and build the Clp project. The code should build out of
the box with default settings.
It is also possible to build Clp with the Visual Studio compiler from the
command line using the procedure for Unix-like environments, using the Msys2
shell or CYGWIN. This is the recommended and best-supported way of building
Clp in Windows from source. To do so, make sure the
cl compiler is in your
path and add
--enable-msvc to build command of
Running clp gives you some hints. It can do a unit test (
clp -unitTest) and solve netlib
-netlibp using primal). It can also solve problems and set tolerances
etc. Just do
and then try
? or setting various stuff.
clp filename #read file, do presolve and dual algorithm clp filename -primalsimplex #use primal instead
On Linux, clp can do file completion and line editing if it can find the history, readline, and termcap packages when building.
If you want to stress the code, you can set various stuff, e.g., dantzig pricing and then go into netlib testing. It is not guaranteed that it will solve all netlib instances if you get too creative. For instance using presolve makes netlib solve faster - but pilot87 prefers a large infeasibility weight. So
clp -presolve on -dualbound 1.0e10 -netlib
There are examples in examples. To create an executable, build
coinbrew as above and then do
cd build/Cbc/master/examples make DRIVER=minimum #build the driver minimum.cpp
or whichever driver you want. A list is in Makefile. Three useful samples are:
minimum.cppThis is the simplest possible program to read an mps file.
defaults.cpp. This does not do much more, but it does it in much more complicated way by specifically setting defaults so it does give more useful information. It also prints a solution in a format similar to that of MPSX.
presolve.cppThis is a good driver for larger problems.
Other ones can get complicated so start simple and work your way up.
If you have
Doxygen available, you can build a HTML documentation by typing
in the build directory. If Clp was built via
coinbrew, then the build
directory will be
./build/Clp/master by default. The doxygen documentation main file
is found at
If you don't have
doxygen installed locally, you can use also find the