passagemath-cmr 10.8.1rc0

passagemath: Combinatorial matrix recognition

passagemath is open source mathematical software in Python, released under the GNU General Public Licence GPLv2+.

It is a fork of SageMath, which has been developed 2005-2025 under the motto “Creating a Viable Open Source Alternative to Magma, Maple, Mathematica, and MATLAB”.

The passagemath fork uses the motto “Creating a Free Passage Between the Scientific Python Ecosystem and Mathematical Software Communities.” It was created in October 2024 with the following goals:

• providing modularized installation with pip,

• establishing first-class membership in the scientific Python ecosystem,

• giving clear attribution of upstream projects,

• providing independently usable Python interfaces to upstream libraries,

• offering platform portability and integration testing services to upstream projects,

• inviting collaborations with upstream projects,

• building a professional, respectful, inclusive community,

• empowering Sage users to participate in the scientific Python ecosystem by publishing packages,

• developing a port to Pyodide for serverless deployment with Javascript,

• developing a native Windows port.

Full documentation is available online.

passagemath attempts to support and provides binary wheels suitable for all major Linux distributions and recent versions of macOS.

Binary wheels for native Windows (x86_64) are are available for a subset of the passagemath distributions. Use of the full functionality of passagemath on Windows currently requires the use of Windows Subsystem for Linux (WSL) or virtualization.

The supported Python versions in the passagemath 10.6.x series are 3.10.x-3.14.x.

About this pip-installable distribution package

This pip-installable distribution passagemath-cmr is a small optional distribution for use with passagemath-modules and passagemath-graphs.

It provides a Cython interface to the CMR library, which implements recognition and decomposition algorithms for:

• Totally Unimodular Matrices

• Network Matrices

• Complementary Totally Unimodular Matrices

• (Strongly) Equimodular and Unimodular Matrices

• Regular Matroids

• Graphic / Cographic / Planar Matrices

• Series-Parallel Matroids

Examples

$ pipx run --pip-args="--prefer-binary" --spec "passagemath-cmr[test]" ipython

In [1]: from passagemath_cmr import *

In [2]: from sage.matrix.matrix_cmr_sparse import Matrix_cmr_chr_sparse

In [3]: M = Matrix_cmr_chr_sparse(MatrixSpace(ZZ, 3, 3, sparse=True), [[1, 0, 1], [0, 1, 1], [1, 2, 3]]); M
Out[3]:
[1 0 1]
[0 1 1]
[1 2 3]

In [4]: M.is_unimodular()
Out[4]: True

In [5]: M.is_strongly_unimodular()
Out[5]: False

Development

$ git clone --origin passagemath https://github.com/passagemath/passagemath.git  # or use your fork
$ cd passagemath
passagemath $ ./bootstrap
passagemath $ source ./.homebrew-build-env         # on macOS when homebrew is in use
passagemath $ export PATH=/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin:/usr/lib/wsl/lib  # on WSL
passagemath $ export PIP_CONSTRAINT="$(pwd)/constraints_cmr.txt"
passagemath $ export PIP_BUILD_CONSTRAINT="$(pwd)/constraints_cmr.txt"
passagemath $ echo "passagemath-categories @ file://$(pwd)/pkgs/sagemath-categories" >> constraints_cmr.txt
passagemath $ echo "passagemath-modules @ file://$(pwd)/pkgs/sagemath-modules" >> constraints_cmr.txt
passagemath $ python3 -m venv cmr-venv
passagemath $ source cmr-venv/bin/activate
(cmr-venv) passagemath $ pip install -v -e pkgs/sagemath-cmr        \
                                        -e pkgs/sagemath-modules    \
                                        -e pkgs/sagemath-categories

Modularized use:

(cmr-venv) passagemath $ pip install -v passagemath-repl
(cmr-venv) passagemath $ sage
... sage.all is not available ...
sage: from passagemath_modules import *
sage: matroids.Uniform(3, 4)
U(3, 4): Matroid of rank 3 on 4 elements with circuit-closures
{3: {{0, 1, 2, 3}}}

In plain Python:

(cmr-venv) passagemath $ python3
>>> from passagemath_modules import *
>>> matroids.Uniform(3, 4)
U(3, 4): Matroid of rank 3 on 4 elements with circuit-closures
{3: {{0, 1, 2, 3}}}

For full functionality of Sage:

(cmr-venv) passagemath $ pip install -v passagemath-standard
(cmr-venv) passagemath $ sage
sage: matroids.Uniform(3, 4)
U(3, 4): Matroid of rank 3 on 4 elements with circuit-closures
{3: {{0, 1, 2, 3}}}