#8986: Add support for convex rational polyhedral cones
----------------------------------+-----------------------------------------
Reporter: novoselt | Owner: mhampton
Type: enhancement | Status: needs_work
Priority: major | Milestone: sage-4.4.4
Component: geometry | Keywords:
Author: Andrey Novoseltsev | Upstream: N/A
Reviewer: Volker Braun | Merged:
Work_issues: |
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Comment(by vbraun):
No, I definitely want `__contains__()` and `contains()` to be the same.
I'm only concerned that a novice user of the package will write
{{{
sage: cone = Cone([[1,0],[0,1]])
sage: (1,1) in cone
False
}}}
and get the (in his eyes) wrong answer without any clue as to what went
wrong. If that would be my first interaction with the package, I'd be
convinced that its computations cannot be trusted :-). Once you understand
the code it is of course obvious why it returned False. The difference to
your example, where a ring is not in a graph, is that here it depends on
the details of the coercion (or not) between `ZZ^n` and `ToricLattice`
that will not be familiar to all users.
One could narrow it down to only raise an exception on tests that run into
this problem, like a test along the lines of
{{{
if (!is_ToricLatticeElement(n)):
try:
[ ZZ(i) for i in n ]
raise ValueError, 'You probably want '+str(n)+' to be a N-lattice
element.'
except:
return False # whatever n is, its not in the cone
}}}
Let me know what you think!
--
Ticket URL: <http://trac.sagemath.org/sage_trac/ticket/8986#comment:9>
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