#13089: Implement weighted projective spaces.
--------------------------------------+-------------------------------------
Reporter: davideklund | Owner: AlexGhitza
Type: enhancement | Status: new
Priority: minor | Milestone: sage-5.1
Component: algebraic geometry | Resolution:
Keywords: | Work issues:
Report Upstream: N/A | Reviewers:
Authors: David Eklund | Merged in:
Dependencies: | Stopgaps:
--------------------------------------+-------------------------------------
Comment (by davideklund):
Right now I apply coordinate_vector() to the images in the quotient of the
basis in dimension +1. Then I make the fan from this data, so I guess the
fan does not live in the quotient lattice but some other lattice of the
same rank. This seems to work. Interesting if one can, as I gather from
your reply, simply tell Sage to construct the fan (with these and these
rays and cones) in the quotient lattice. If there were problems with this
feature perhaps a good way of debugging is to use it, here for example.
Replying to [comment:5 novoselt]:
> Not all WPs are (singular) Fano and general toric varieties are handled
by PPL so there are no dimension limits.
>
> If one of the weights is one, e.g. WP(1,1,4,6), then one can take for
the fan rays the standard basis plus "negative weights except for one 1",
i.e. (-1,-4,-6).
>
> In general you take the standard basis of dimension+1 and quotient by
the weights. If this works - great, I just was not sure if there are still
problems with fans in quotient lattices in Sage - there were some but we
were gradually improving the situation.
--
Ticket URL: <http://trac.sagemath.org/sage_trac/ticket/13089#comment:7>
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 post to this group, send email to [email protected].
To unsubscribe from this group, send email to
[email protected].
For more options, visit this group at
http://groups.google.com/group/sage-trac?hl=en.
