#11200: Add fibration check to FanMorphism
----------------------------+-----------------------------------------------
Reporter: novoselt | Owner: mhampton
Type: enhancement | Status: needs_review
Priority: major | Milestone: sage-4.7.1
Component: geometry | Keywords: toric
Work_issues: | Upstream: N/A
Reviewer: Volker Braun | Author: Andrey Novoseltsev
Merged: | Dependencies: #10140, #10882
----------------------------+-----------------------------------------------
Changes (by vbraun):
* reviewer: => Volker Braun
Comment:
I like the functionality, but you need to check surjectivity of the map of
toric varieties, not just the map of vector spaces. The `is_surjective()`
method should do that but is broken:
{{{
sage: P1 = toric_varieties.P1()
sage: A1 = toric_varieties.A1()
sage: phi = FanMorphism(matrix([[1]]), A1.fan(), P1.fan())
sage: phi.is_fibration()
True
sage: phi.is_surjective()
True
}}}
But thats neither a fibration nor a surjective map.
--
Ticket URL: <http://trac.sagemath.org/sage_trac/ticket/11200#comment:3>
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.
