#20956: Number of reflections in Weyl and Coxeter groups can be computed faster
-------------------------------------------------+-------------------------
Reporter: stumpc5 | Type:
| enhancement
Status: new | Priority: major
Milestone: sage-7.3 | Component:
Keywords: reflection group, coxeter | combinatorics
group, subword complex, days80 | Merged in:
Authors: | Reviewers:
Report Upstream: N/A | Work issues:
Branch: | Commit:
Dependencies: | Stopgaps:
-------------------------------------------------+-------------------------
For Weyl groups, we have
{{{
sage: W = WeylGroup(['E',7])
sage: %timeit len(W.long_element(as_word=True))
10 loops, best of 3: 98.6 ms per loop
sage: %timeit W.number_of_reflections()
1 loop, best of 3: 208 ms per loop
}}}
and for Coxeter groups, we have
{{{
sage: W = CoxeterGroup(['E',7])
sage: %timeit len(W.long_element(as_word=True))
1 loop, best of 3: 206 ms per loop
sage: %timeit W.number_of_reflections()
1 loop, best of 3: 378 ms per loop
}}}
I think that we should either use the longest element, or, even better, to
speed the computations of the degrees (which are used to compute the
number of reflections).
--
Ticket URL: <https://trac.sagemath.org/ticket/20956>
Sage <http://www.sagemath.org>
Sage: Creating a Viable Open Source Alternative to Magma, Maple, Mathematica,
and MATLAB
--
You received this message because you are subscribed to the Google Groups
"sage-trac" group.
To unsubscribe from this group and stop receiving emails from it, send an email
to [email protected].
To post to this group, send email to [email protected].
Visit this group at https://groups.google.com/group/sage-trac.
For more options, visit https://groups.google.com/d/optout.
