#17197: Bug creating Polyhedron from lines in number field
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Reporter: mbell | Owner:
Type: defect | Status: new
Priority: major | Milestone: sage-6.4
Component: geometry | Keywords: Polyhedron, Number field
Merged in: | Authors:
Reviewers: | Report Upstream: N/A
Work issues: | Branch:
Commit: | Dependencies:
Stopgaps: |
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I reported this to the google group
(https://groups.google.com/forum/#!topic/sage-support/ew0bnGzjm98) but was
told to repeat it here.
To create polyhedra quickly, the final suggestion in the Polyhedron
documentation
(http://www.sagemath.org/doc/reference/geometry/sage/geometry/polyhedron/constructor.html
#base-rings) is to work in a set number field. Although this appears to
work for setting vertices, it does not appear to work for lines (or rays).
For example:
{{{
sage: var('x')
x
sage: K.<sqrt3> = NumberField(x^2-3, embedding=1.732)
sage: P = Polyhedron(lines=[(1,sqrt3)])
sage: P
A 1-dimensional polyhedron in (Number Field in sqrt3 with defining
polynomial x^10 + x^2 - 3)^2 defined as the convex hull of 1 vertex and 2
rays
sage: P.rays()
(A ray in the direction (0, -sqrt3), A ray in the direction (1, sqrt3))
}}}
This should be compared with:
{{{
sage: P = Polyhedron(lines=[(1, sqrt(3))])
sage: P
A 1-dimensional polyhedron in (Symbolic Ring)^2 defined as the convex hull
of 1 vertex and 1 line
}}}
and
{{{
sage: P = Polyhedron(lines=[(1, sqrt(3))], base_ring=AA)
sage: P
A 1-dimensional polyhedron in AA^2 defined as the convex hull of 1 vertex
and 1 line
}}}
Additionally, how can a "1-dimensional polyhedron" be "defined as the
convex hull of 1 vertex and 2 rays"?
--
Ticket URL: <http://trac.sagemath.org/ticket/17197>
Sage <http://www.sagemath.org>
Sage: Creating a Viable Open Source Alternative to Magma, Maple, Mathematica,
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