pypolymake
==========

What is it?
-----------

The Python module pypolymake provides wrappers for `polymake version 3.1
<https://polymake.org/doku.php>`_. This module will not compile with
older version of polymake.

The language has been kept as close as possible as the original. The
following polymake construction::

    polytope> $c = cube(5);
    polytope> print $c->F_VECTOR;
    32 80 80 40 10
    polytope> $g = $c->GRAPH;
    polytope> print $g->DIAMETER;
    5

is translated in Python as::

    >>> from polymake import *
    >>> c = cube(5)
    >>> print(c.F_VECTOR)
    (32, 80, 80, 40, 10)
    >>> g = c.GRAPH
    >>> print(g.DIAMETER)
    5

The library is currently under development and is compatible with Python2 and
Python3. As it is under development, many things are not working and are likely
to break.

Installation and source code
----------------------------

Just run the following command to install pypolymake

    $ pip install git+https://github.com/videlec/pypolymake [--user] [--upgrade]

If you want to use it inside Sage, you need a version more recent than Sage
8.0.beta0 (earlier versions ships polymake version 2.7, not compatible with
pypolymake). To install polymake and pypolymake run

    $ sage -i polymake
    $ sage -pip install git+https://github.com/videlec/pypolymake [--user] [--upgrade]

### Notes

If polymake headers or libraries are installed in a non standard location you
may need to set the environment variables CFLAGS, CXXFLAGS, LDFLAGS. For example,
on OS X, you need to update LDFLAGS as::

    $ export LDFLAGS="-L/System/Library/Perl/5.18/darwin-thread-multi-2level/CORE/ $LDFLAGS"
    $ python setup.py install --user

You might also need to set LD_LIBRARY_PATH before starting Python if the shared
library of polymake (libpolymake.so) is not in a standard directory. For example

    $ LD_LIBRARY_PATH=/my/path/to/lib/ ipython

For SageMath users
------------------

If pypolymake is used inside SageMath then conversion from and to sage objects are
available. Most polymake objects have a `.sage()` method and you can use
`polymake.polymake` as a generic convertor. For example::

    sage: import polymake
    sage: p = polymake.polymake(polytopes.dodecahedron())
    sage: p
    Polytope<QuadraticExtension<Rational>>
    sage: p.VERTICES
    1 3-1r5 3-1r5 3-1r5
    1 -1+1r5 -4+2r5 0
    ...
    1 -3+1r5 -3+1r5 -3+1r5
    1 1-1r5 4-2r5 0
    sage: print(p.VERTICES.sage())
    [           1   -sqrt5 + 3   -sqrt5 + 3   -sqrt5 + 3]
    [           1    sqrt5 - 1  2*sqrt5 - 4            0]
    ...
    [           1    sqrt5 - 3    sqrt5 - 3    sqrt5 - 3]
    [           1   -sqrt5 + 1 -2*sqrt5 + 4            0]

Warning: the cohabitation between sage and polymake is not perfect. If you do
use polymake in sage *always* import sage first and then polymake. More precisely,
if you launch a simple python console and do 'import polymake' followed by
'import sage.all' it is most likely to end up with a (not yet identified)
SEGFAULT.

License
-------

The library pypolymake is distributed under the terms of the GNU General Public
License (GPL) as published by the Free Software Foundation; either version 3 of
the License, or (at your option) any later version (see http://www.gnu.org/licenses/)

Authors
-------

This project has been started by Burcin Erocal in 2011 and continued
by Vincent Delecroix in 2016

