On Jul 15, 12:15 pm, "Harald Schilly" <harald.schi...@gmail.com>
> I am searching for interesting content and this time I want to ask
> everyone who has used Sage for his or her research or in education in
> class to write a short success story. It should talk about how it was
> used and the general and personal experience. Just some sentences to
> give new users a first impression of Sage.
I hope the following description isn't too long...
Computation of cohomology rings of finite p-groups with coefficients
How Sage and its components were used:
- I use Gap to compute certain elementary abelian subgroups.
- Due to Cython, i can use C-programs of David Green for computing
- Cython is a very nice python-like programming language, in which i
created classes for cochains, chain maps, cohomology rings etc.
- In order to find a minimal generating set and a minimal set of
relations for a cohomology ring, i need Gröbner basis computations in
graded commutative rings (or simply "commutative", in characteristic
2); Singular does that job.
- Computation time for the cohomology rings of all 267 groups of order
64: About 2h40min in total (on a single CPU).
- Work in progress: Computation of the cohomology rings of groups of
order 128. So far successful for 2221 groups (i.e., 107 are still
missing). Computation time so far: 15 days, parallely on 4 CPUs.
General and personal experience:
- After learning a few days, wrapping the C-programs was surprisingly
- Writing Cython-code is fun!
- Communication with Singular via an ascii interface was painful until
i found some tricks to reduce the traffic.
- The non-commutative part of Singular has serious bugs. Hence, unless
i find a work around, i can use my programs only in characteristic 2.
- When problems occured, the Sage community was very responsive (Thank