#9972: Add fan morphisms
------------------------------------------------+---------------------------
Reporter: novoselt | Owner: mhampton
Type: enhancement | Status: needs_info
Priority: major | Milestone: sage-4.6.1
Component: geometry | Keywords:
Author: Andrey Novoseltsev, Volker Braun | Upstream: N/A
Reviewer: Volker Braun, Andrey Novoseltsev | Merged:
Work_issues: |
------------------------------------------------+---------------------------
Changes (by vbraun):
* status: needs_review => needs_info
Comment:
Why is `preimage_cones` not the preimage of `image_cones`? This confuses
me:
{{{
sage: cone = f.image_cone( Cone([(1,0),(0,1)]) )
sage: [ cone is f.image_cone(c) for c in f.preimage_cones(cone) ]
[True, True, True, False, False, False]
}}}
I understand that it is working as documented, but it seems like it would
be more useful to actually return the preimage cones. In other words, take
preimage cones in the sense of fan morphisms and not in the sense of
convex sets.
If one is interested in all cones mapping geometrically into a given cone
one could always construct the `Fan` of the (fan morphism) preimage cones.
--
Ticket URL: <http://trac.sagemath.org/sage_trac/ticket/9972#comment:53>
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.
