#15224: Iterate over the points of a toric variety
-------------------------------------+-------------------------------------
Reporter: vbraun | Owner:
Type: enhancement | Status: new
Priority: major | Milestone: sage-5.13
Component: algebraic | Resolution:
geometry | Merged in:
Keywords: sd53 | Reviewers:
Authors: Volker Braun | Work issues:
Report Upstream: N/A | Commit:
Branch: | e9f9710bd26adeb8ffaf7205343cbd9f78bbac0a
u/vbraun/toric_variety_points | Stopgaps:
Dependencies: |
-------------------------------------+-------------------------------------
Comment (by ursula):
We should add a documentation example where the fan is not complete. The
blowup of a point, where the fan has two cones, one from [(1,0),(1,1)] and
one from [(0,1),(1,1)] would be a nice choice: in that setting, you can
see a projective line when the coordinate corresponding to (1,1) is 0.
This code throws errors when the toric variety has torus factors (that is,
when the rays of the fan do not span the vector space associated with N).
For example:
V = ToricVariety(Fan([Cone([(1,0)])]))
VF = V.change_ring(GF(3))
list(VF.point_set())
yields:
ValueError: there must be 2 coordinates! Got only 1: (0,)
This behaviour does not really surprise me. When a toric variety has
torus factors, the choice of homogeneous coordinates is non-canonical. I
assume homogeneous coordinates are not implemented in Sage for such a
variety.
--
Ticket URL: <http://trac.sagemath.org/ticket/15224#comment:18>
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 http://groups.google.com/group/sage-trac.
For more options, visit https://groups.google.com/groups/opt_out.
