#17030: Knot Theory as a part of GSoC 2014.
-------------------------------------+-------------------------------------
Reporter: amitjamadagni | Owner: amitjamadagni
Type: enhancement | Status: needs_work
Priority: major | Milestone: sage-6.9
Component: algebraic | Resolution:
topology | Merged in:
Keywords: | Reviewers: Miguel Marco, Karl-
Authors: Amit Jamadagni, | Dieter Crisman, Frédéric Chapoton
Miguel Marco | Work issues:
Report Upstream: N/A | Commit:
Branch: | 8f4ec1977612c42da767931683dae92ba17e4bb0
public/ticket/17030 | Stopgaps:
Dependencies: |
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Comment (by fuglede):
I pushed those changes to {{{u/fuglede/17030}}}
([https://github.com/fuglede/sage/commit/72bb738149541d2360c7ab131ae8830c5dbb8aee
GH mirror] of the commit if you just want to have a quick look). One
obvious pain is that the two algorithms give different results when the
link is not the trace closure of the braid used to initialize it, which
happens when one has crossing-less strands, as the following example
illustrates:
{{{
sage: B = BraidGroup(3)
sage: b = B([1])
sage: L = Link(b)
sage: b.components_in_closure()
2
sage: L.number_of_components()
1
sage: L.jones_polynomial(algorithm='jonesrep')
-sqrt(t) - 1/sqrt(t)
sage: L.jones_polynomial(algorithm='statesum')
1
}}}
Of course, this is not specific to Jones related stuff:
{{{
sage: B = BraidGroup(3)
sage: b = B([1])
sage: b.alexander_polynomial()
0
sage: Link(b).alexander_polynomial()
1
}}}
The branch also corrects a couple of typos.
--
Ticket URL: <http://trac.sagemath.org/ticket/17030#comment:141>
Sage <http://www.sagemath.org>
Sage: Creating a Viable Open Source Alternative to Magma, Maple, Mathematica,
and MATLAB
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