This Python package provides a wrapper to the C++ Parma Polyhedra Library (PPL).
The whole package started as a fork of a tiny part of the Sage software.
The names of objects and methods are the same as in the library:
>>> import ppl
>>> x = ppl.Variable(0)
>>> y = ppl.Variable(1)
>>> z = ppl.Variable(2)
>>> cs = ppl.Constraint_System()
>>> cs.insert(x >= 0)
>>> cs.insert(y >= 0)
>>> cs.insert(z >= 0)
>>> cs.insert(x + y + z == 1)
>>> poly = ppl.C_Polyhedron(cs)
>>> poly.minimized_generators()
Generator_System {point(1/1, 0/1, 0/1), point(0/1, 1/1, 0/1), point(0/1, 0/1, 1/1)}The available objects and functions from the ppl Python module are:
- Variable, Variables_Set, Linear_Expression (defined in ppl.linear_algebra)
- MIP_Problem (defined in ppl.mip_problem)
- C_Polyhedron, NNC_Polyhedron (defined in ppl.polyhedron)
- Generator, Generator_System, Poly_Gen_Relation, point, closure_point, ray, line (defined in ppl.generator)
- Constraint, Constraint_System, Poly_Con_Relation, inequality, equation, strict_inequality (defined in ppl.constraint)
The project is available at Python Package Index and can be installed with pip:
$ pip install pplpy
Note that if you have gmp and ppl installed in a non standard directory (e.g. you use brew on MacOSX) then you need to set appropriately the variables CFLAGS before calling pip. For example:
$ export CFLAGS="-I/path/to/gmp/include/ -L/path/to/gmp/lib/ -I/path/to/ppl/include/ -L/path/to/ppl/lib $CFLAGS" $ pip install pplpy
All Python classes from pplpy are extension types and can be used with Cython. Each extension type carries an attribute thisptr that holds a pointer to the corresponding C++ object from ppl.
A complete example is provided with the files tests/testpplpy.pyx and tests/setup.py.
You can find the latest version of the source code on github: https://github.com/sagemath/pplpy
An online version of the documentation is available at https://www.sagemath.org/pplpy/
Compiling the html documentation requires make and sphinx. Before building the documentation, you need to install the pplpy package (sphinx uses Python introspection). The documentation source code is contained in the repository docs where there is a standard Makefile with a target html. Running make html in the docs repository builds the documentation inside docs/build/html. For more configuration options, run make help.
pplpy is distributed under the terms of the GNU General Public License (GPL) 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/.
On Debian/Ubuntu systems the dependencies can be installed with:
$ sudo apt-get install libgmp-dev libmpfr-dev libmpc-dev libppl-dev cython3 python3-gmpy2 python3-cysignals-pari