Stallings Graphs Research Code¶
This is the reference manual for Pascal Weil’s stallings_graphs
Research Code extension to the Sage mathematical software system. Sage is free open source math software that supports research and teaching in algebra, geometry, number theory, cryptography, and related areas.
About this package¶
stallings_graphs
Research Code implements tools to experiment with finitely generated subgroups of infinite groups in Sage, via a set of new Python classes. Many of the modules correspond to research code written for published articles (random generation, decision for various properties, etc). It is meant to be reused and reusable (full documentation including doctests).
Comments are welcome.
Install¶
To install this module, you do:
sage -pip install stallings_graphs
or:
sage -pip install http://www.labri.fr/perso/weil/software/stallings_graphs-0.2.tar.gz
To use this module, you need to import it:
from stallings_graphs import *
This reference manual contains many examples that illustrate the usage of
stallings_graphs
. The examples are all tested with each release of stallings_graphs
, and
should produce exactly the same output as in this manual, except for line
breaks.
Licence¶
This work is licensed under a Creative Commons Attribution-Share Alike 3.0 License.
Prerequisites¶
Installing stallings_graph
requires a working SageMath installation. Depending on the usage (especially to produce LaTeX, pdf, png outputs), it might be necessary to install the optional package dot2tex
:
sage -i dot2tex
as well as the external packages ImageMagick
, Graphviz
.
On OSX, after installing Homebrew
, one may do:
sudo brew install graphviz imagemagick
On Debian or Ubuntu, one may do:
sudo apt install graphviz imagemagick
Note that graphviz
must be installed before dot2tex
.
The package stallings_graph
also uses Sébastien Labbé’s slabbe
package and Thierry Coulbois’s train_track
package. Both are automatically installed when stallings_graphs
is installed.
Useful links¶
- On PyPI: https://pypi.org/project/stallings-graphs/
- HTML Documentation: https://www.labri.fr/perso/weil/software/version-0-2/html/
- PDF Documentation: https://www.labri.fr/perso/weil/software/version-0-2/stallings_graphs.pdf
- Professional homepage link: https://www.labri.fr/perso/weil/software/
- The
slabbe
package: https://pypi.org/project/slabbe/ - The
train_track
package: https://pypi.org/project/train-track/
Release history¶
Version 0.2, released September 2020 (Pascal Weil)
- the package now works with Python 3
- some bug fixes
- addition of new methods on finitely generated subgroups, including the decision of free factors and the computation of the lattice of algebraic extensions of a subgroup
- definition and usage of morphisms between free groups, by means of a connection to Thierry Coulbois’s
train_track
package
Version 0.1, released March 2019 (Pascal Weil)
Finitely generated subgroups of free groups¶
Partial injections¶
References, Indices and tables¶
[BNW2008] |
|
[MVW2007] |
|
[SW2008] |
|
[T2006] |
|