Change error message in construction of polyhedron object

[jipilab]

The current error message given by

    sage: Polyhedron([[sqrt(2)]])
    Traceback (most recent call last):
    ...
    ValueError: for polyhedra with floating point numbers, the only allowed ring is RDF with backend 'cdd'

should be replaced by "ValueError?: the only allowed inexact ring is RDF with backend 'cdd'"

[moritz]

Wouldn't it be good, if it automatically detected AA? (Perhaps not..)

sage: P = Polyhedron([[sqrt(2)]], base_ring=AA)
sage: P.vertices()
(A vertex at (1.414213562373095?),)

[vdelecroix]

Replying to moritz:

Wouldn't it be good, if it automatically detected AA? (Perhaps not..)

sage: P = Polyhedron([[sqrt(2)]], base_ring=AA)
sage: P.vertices()
(A vertex at (1.414213562373095?),)

I don't want to special case input coming from the symbolic ring in the polyhedron code. This is the kind of thing that would have to be repeated everywhere. So either sqrt(2) should be a proper number field element (possibly AA) or this will stay as it is.

[jipilab]

Replying to moritz:

Wouldn't it be good, if it automatically detected AA? (Perhaps not..)

sage: P = Polyhedron([[sqrt(2)]], base_ring=AA)
sage: P.vertices()
(A vertex at (1.414213562373095?),)

Forcing the base ring to be algebraic numbers is a bit "DWIM"... so I would allow it as it is above. If the user is lazy and still puts the base ring to be AA with square roots everywhere... it's still nice to be able to get what you want, but it should not allow to simply but symbolic stuff at all.

[jipilab]

New commits:

​18293d5	initial commit
​e1904c6	22572: first draft of polyhedra tutorial
​5a09b69	22572: revamp polyhedra tutorials
​db5e413	Updated to 8.2.b5, fixed many errors
​62c5d56	Merge branch 'public/22572v8.2b5' of trac.sagemath.org:sage into 24835
​84ec284	Fixed the tutorial

[git]

Branch pushed to git repo; I updated commit sha1. New commits:

​85dc6f4

pep8

[git]

Branch pushed to git repo; I updated commit sha1. New commits:

​5e2b8e5

Merge branch 'develop' into 24835

[git]

Branch pushed to git repo; I updated commit sha1. Last 10 new commits:

​31edde6	Completed a comment
​231cd56	deleted trailing whitespace
​f685c64	fixed some typos in lectures.rst
​7f5e125	fixed typos in polyhedra_quickref.rst
​bd6c356	LateX -> LaTeX in polytope_tikz.rst
​b1ce45b	Several other corrections
​d526f70	renamed tutorial files
​d7896f8	Merge branch 'develop' into 22572
​597b802	Merge branch sage8.2.rc1 into 22572
​b32299a	Merge branch '22572' into 24835

[moritz]

Looks good!

[git]

Branch pushed to git repo; I updated commit sha1 and set ticket back to needs_review. New commits:

​eee533a	Corrections from review
​b74ae85	Made tests pass
​7005c9e	Merge branch '22572' into 24835

[jipilab]

Merge the dependency.