.. _spkg_lrslib:

lrslib: Reverse search algorithm for vertex enumeration and convex hull problems
================================================================================

Description
-----------

lrslib implements the linear reverse search algorithm of Avis and
Fukuda.

See the homepage (http://cgm.cs.mcgill.ca/~avis/C/lrs.html) for details.

We use an autotoolized version from
https://github.com/mkoeppe/lrslib/tree/autoconfiscation

License
-------

lrslib is released under a GPL v2+ license.


Upstream Contact
----------------

David Avis, avis at cs dot mcgill dot edu.

Dependencies
------------

To build and install the "plrs" binary, a multi-thread version of lrs,
need to first install the full Boost package ("sage -i boost").

If the package finds an MPI C++ compiler script (mpic++), it also builds
and installs the "mplrs" binary, a distributed version of lrs using MPI.

(Sage currently does not make use of plrs and mplrs.)


Special Update/Build Instructions
---------------------------------

Type
----

optional


Version Information
-------------------

package-version.txt::

    062+autotools-2017-03-03.p1


Equivalent System Packages
--------------------------

arch:

.. CODE-BLOCK:: bash

    $ sudo pacman -S  lrslib

conda:

.. CODE-BLOCK:: bash

    $ conda install lrslib

opensuse:

.. CODE-BLOCK:: bash

    $ sudo zypper install lrslib

See https://repology.org/project/lrslib/versions

However, these system packages will not be used for building Sage
because spkg-configure.m4 has not been written for this package;
see https://trac.sagemath.org/ticket/27330