# Welcome to the COIN Vol Project
## Introduction
Vol (Volume Algorithm) is an open-source implementation of a subgradient
method that produces primal as well as dual solutions. The primal solution
comes from estimating the volumes below the faces of the dual problem. This is
an approximate method so the primal vector might have small infeasiblities
that are negligible in many practical settings. The original subgradient
algorithm produces only dual solutions.
## Background/Download
Vol is written in C++ and is released as open source code under the
[Eclipse Public License](http://www.opensource.org/licenses/eclipse-1.0)(EPL).
To get all of the dependencies and build the `Vol` package, do
```
git clone https://github.com/coin-or/Vol
Vol
git clone https://github.com/coin-or-tools/BuildTools
BuildTools/get.dependencies fetch
BuildTools/get.dependencies build
```
To test by building an application, do
```
cd build/Vol/examples/VolUfl
make
./ufl
```
## Included Projects
If you download the Vol package, you get
[these](https://github.com/coin-or/Vol/blob/master/Dependencies)
additional projects.
## Doxygen Documentation
If you have `Doxygen` available, you can build the html documentation by typing
```
make doxydoc
```
in the `Vol` directory. Then open the file `coin-Vol/doxydoc/html/index.html` with a browser.
Note that this creates the documentation for the `Vol`
package as a whole. If you
prefer to generate the documentation only for a subset
of these projects, you can edit the file `Vol/doxydoc/doxygen.conf` to exclude directories
(using the `EXCLUDE` variable, for example).
If `Doxygen` is not available, you can use the link to the {{{Vol}}} html documentation listed below.
## Documentation
* [Overview of different directories](https://projects.coin-or.org/Vol/attachment/wiki/WikiStart/volDoc.pdf?format=raw)
* [The Volume Algorithm: Producing Primal Solutions With a Subgradient Method](http://domino.watson.ibm.com/library/cyberdig.nsf/a3807c5b4823c53f85256561006324be/7a1b25774639540a852565be0070cfb5?OpenDocument)
* [On Some Difficult Linear Programs Coming from Set Partitioning](http://domino.watson.ibm.com/library/cyberdig.nsf/a3807c5b4823c53f85256561006324be/53731ca97769f3838525672f0070dc2b?OpenDocument)
* [Solving Large Scale Uncapacitated Facility Location Problems](http://domino.watson.ibm.com/library/cyberdig.nsf/a3807c5b4823c53f85256561006324be/08e1ac62bb877f9a852567b500500996?OpenDocument)
* [Near-Optimal Solutions to Large Scale Facility Location Problems](http://domino.watson.ibm.com/library/cyberdig.nsf/a3807c5b4823c53f85256561006324be/215bca4e7e2406ec852568430076860c?OpenDocument)
* [Solving Steiner Tree Problems in Graphs with Lagrangian Relaxation](http://domino.watson.ibm.com/library/cyberdig.nsf/a3807c5b4823c53f85256561006324be/4a61544906b57a6d8525696c0057f955?OpenDocument&Highlight=0,barahona)
* [Vol html documentation](http://www.coin-or.org/Doxygen/Vol/hierarchy.html)
* [COIN-OR Initiative](http://www.coin-or.org/)